this is bbc news. the headlines at 10pm: the online forum reddit says it believes leaked government documents, detailing uk—us trade talks, and posted on its site, are linked to russia. oceans are running out of oxygen, warn scientists, as global temperature rises put many species of fish at risk of extinction. a chinese american researcher is freed by iran in a prisoner exchange with the us but president trump says he won't rest until they release all wrongfully detained us citizens. and coming up, anthony joshua vs andy

ruiz. the world title re—match is under way, we'll bring you the result at the end of the fight. and we'll be taking an in—depth look at the papers with nigel nelson, the political editor of the sunday people and sunday mirror, and jo phillips, political commentator, who was an adviser to former liberal democrats‘ leader, paddy ashdown. questions are being raised about russian interference in the election after possible links emerged between russia and leaked documents detailing trade discussions between the united states and the uk. the papers were used by labour to claim the conservatives will include the nhs in any deal

with the americans after brexit, which they've denied. the documents appeared on the online discussion forum, reddit, which said they were linked toa campaign originating from russia. let's speak now to the journalist and analyst ben nimmo, who broke this story. he works for the social media investigations company graphika. really the key question here is how on earth did these documents fall into the hand of the person who is responsible for putting them out online? that is the big question. it has been the question since the resemblance to the russian operation became clear, with reddit‘s statement last night, the question is even bigger. what we know is that the way the leaks were posted and amplified online at the end of october, very closely resembled a

russian operation that was exposed and attributed back injune this year. we know from reddit last night that their conclusion from looking at the stuff on their platform is that indeed the resemblance is there because the two operations were linked so the trade links, according to reddit, were pushed by the same operation is attributed to russia earlier in the year. we don't how the leaks earlier in the year. we don't how the lea ks got earlier in the year. we don't how the leaks got there and that is really the biggest question. working out how they ended up online and thatis out how they ended up online and that is really the biggest question. working out how they ended up online in the first place. you put together a report as part of graphika, what will your conclusions? it is very ha rd to will your conclusions? it is very hard tojudge the will your conclusions? it is very hard to judge the motivations of any information operation because any operation is based on deceit and that can have many levels. a particular twitter account on the 23rd of october was tweeting a link to documents. each time it tweeted was either to

a journalist or a member of the opposition party. it wasn't just addressing member of the opposition party. it wasn'tjust addressing it member of the opposition party. it wasn't just addressing it to member of the opposition party. it wasn'tjust addressing it to labour but to the lib dems and the snp. the content but to the lib dems and the snp. the co nte nt of but to the lib dems and the snp. the content of the tweets said that it shows that the price that the conservatives and borisjohnson are willing to pay so it was somewhat negative towards the government but thatis negative towards the government but that is to slander a lead to confirm that is to slander a lead to confirm that it was designed to discomfort the government. that doesn't seem to be the impression that we need to have more information on that. these documents were actually released backin documents were actually released back in october. they only gained traction oncejeremy corbyn branched them at that news conference in november. how risky a move was this by the labour leader in terms of verifying them? well, one of the big questions is how the documents actually got as far as the labour leader. we know there is a unknown persona e—mailing them to various activists who are interested in the trade talks around the 20th or

21st of november or perhaps slightly later and we don't know whether that persona was associated with the operation so there is still question that has not been cleared up. we can't say for sure that it was the operation themselves they got it as far as the labour party but the bigger picture is that leaks are a very difficult thing to deal with and they are one of the most dangerous parts of any information operation, precisely because they use real documents was not the big difference between these leaks and the russian operation was that the russian operation in june the russian operation was that the russian operation injune used fake so it is easy to fact check but when you are using a real leak there much more complex issues, are they genuine, are they newsworthy, are they of political importance? it is a very complex calculation and it shows, just as in 2016, it shows how much of an impact leaking can have. thank you very much indeed.

and we'll find out how this story, and many others, are covered in tomorrow's front pages at 10:30pm and 11:30pm this evening in the papers. our guestsjoining me tonight are nigel nelson, the political editor of the sunday people and sunday mirror, and jo phillips, political commentator, who was an adviser to the former liberal democrat leader, paddy ashdown. there's fresh warning that climate change and nutrient pollution are diminishing oxygen levels in our oceans. that's the conclusion of the biggest study of its kind, undertaken by the group "the international union for the conservation of nature". while nutrient run—off has been known for decades, researchers say that climate change is making the lack of oxygen worse, and is having an impact on certain species of fish. earlier my colleague, shaun ley, spoke to minna epps, the director of the iucn's global marine and polar programe, who's attending

the climate summit in madrid. what we are seeing from the middle of the last century is a 2% decline in the global average. within that average you have lots of different regional differences and 2% might not seem like a lot but if you think about it in the terms of the climate change debate, we know that even 1 degree will have a huge impact. in the coastal areas, but we are now seeing it in the open sea. we are looking at the reporting of your work that around 700 sites have been identified as having low oxygen levels, up from only 45 in the 1960s. admittedly over several decades but that is a significant rise? yes and the low oxygen zones have

increased by 11.5 square kilometres and that is the size of the eu so this is a huge expansion of low oxygen zones. what are the impacts on different species, presumably some species need less oxygen? they are smaller and so on. presumably some of them are very dependent on the amount of oxygen in the water? that is very true. for example, the species which have a high metabolic rate, let's say the swordfish or tuna, some of these species, they are actually dependent on oxygen rich water. they will be most vulnerable to the change. deoxygenation also results in other changes that will affect them. it might alter the energy and biochemical cycles affecting these systems that bring nutrients and oxygen rich waters to

the surface. we are seeing for example that if you take the blue marlin, which dives about half a mile down to collect its feed, that is what they're doing outside the coast of california and we are seeing outside the coast of costa rica and guatemala, they stay by the surface because they want to stay where there is more oxygen rich water which means they become more vulnerable. not only is their habitat shrinking but ultimately we will lose biomass. in terms of the impact, is there any measures that could reduce this? we are talking about mitigating effects from global warming but when we talk about the oceans and the loss of oxygen, how do you reoxygenate the ocean? very good question! it impacts biodiversity, biomass and habitats and energy and biochemical cycles and it is not just fisheries but also other marine mammals that will be affected indirectly through the food web. what can be

done? there is a solution and that is that we must urgently, drastically cut co2 emissions. we need to invest more in nature by protecting and restoring nature. but again, what else we can do is also to reduce those climate stressors or the non—climate stressors, like overfishing, that puts additional pressure. reducing overfishing and over—pollution to the oceans would drastically improve the situation. given where you are, the message you are sending and delivering not just to the public but to delegates, the people who have to negotiate how we get from the targets to implementing? i truly believe that the decisions being made here will actually determine the future of the oceans. will they be thriving and nutrient rich with biodiversity or will they be depleted and irreversibly damaged? i think the decisions being made

here will have a difference so we need to have more ambitious targets collectively. so all the naturally determined contributions which the state is responsible for, that collectively must be much more ambitious.

of course there should be no interference in our political system bya interference in our political system by a donald trump or the russians. we will have the latest analysis. also tonight, the us and iran carry out a prisoner swap. australia firefighters warned they cannot stop a blaze that is bigger than the city itself has anthonyjoshua regained his title in saudi arabia?

good evening. questions are being raised about russian interference in the election after possible links emerge detailing trade talks between the united states and the emerge detailing trade talks between the united states and the uk. emerge detailing trade talks between the united states and the uk. the papers were used by labour to claim the conservatives will include the nhs in any deal with the americans after brexit, which they have denied. the documents appeared on the online discussion forum reddit which said they were linked to a campaign originating from russia. a leaked government document, highlighted by labour, containing details of initial discussions on trade between uk and us officials. its authenticity is not disputed. what it proves has been hotly debated. how it came to be made public is unclear. jeremy corbyn, campaigning in wales today as the online news site reddit — where the document first surfaced — said it was posted by an account linked to a campaign originating in russia. he insisted publishing the document was in the public interest

and argued the government should release a parliamentary report into russian interference. the prime minister has answers to give which he refuses to do about russian donations to the tory party or the report that he is sitting on about russian interference in british politics. of course there should be no interference in our british political system by donald trump or the russians. promoting money for grassroots football in england on a campaign visit in stockport, borisjohnson said the government had played by the rules, but acknowledged the source of the leak needed to be found. i do think we need to get to the bottom of that. as far as i am aware, we have not established the truth about that but what i certainly think is that document, whatever it was intended to prove, did not prove what jeremy corbyn and the labour party hoped that it would prove. campaigning for votes in st albans, jo swinson said any sign of foreign interference was worrying,

but singled out borisjohnson for not yet publishing the mps' report. it is shocking that the prime minister is sitting on a report from the intelligence and security committee into this very topic, into whether or not russia or other countries have tried to interfere with our democracy. the prime minister has decided that he will keep that secret and that is appalling. the party leaders sounded serious today on this subject of foreign interference but from now on, expect them to focus firmly on their main messages to voters as the campaign enters its final days. jonathan blake, bbc news. our security correspondent, gordon corera, is here with me. gordon, is this being looked at as possible russian interference? the campaign started with the questions about russian interference and that report not being published and that report not being published and now as it comes to an end there is the question of whether we have seen some kind of interference. certainly that possibility is being taken seriously but it is also

very murky. it looks like one social media account, possibly linked to russia, was pushing an unscented copy of those trade talk documents backin copy of those trade talk documents back in october —— uncensored. but it was largely ignored until another version obtained by the labour party was used and then this other version came out few days later so it looks like russia might have been in the mix somehow but still a lot of things and clear, including how that uncensored document came to the surface in the first place. there is a range of possibilities from the most serious that the russian state somehow hacked the british state, stole the document leaked it to commit less surprising that someone here for political reasons perhaps lea ked here for political reasons perhaps leaked the document and the russian cause mischief by taking advantage of that. they are certainly taking this seriously but they are remaining tight—lipped, precisely

because of the political sensitivities as this campaign reaches the final days. as the campaign enters its final days, let's take a look at some of today's other election news. the conservatives say they're investigating three of their parliamentary candidates over allegations of anti—semitism. the party says it's looking into items they have posted or shared online. labour is planning to make england 5 entire bus fleet electric by 2030 if it wins the general election. the project would be funded by £4 billion over ten years from the party 5 green transformation fund. campaigning in hertfordshire, the liberal democrats have pledged to scrap business rates to help small firms and have promised more more help for entrepreneurs. snp leader nicola sturgeon has been campaigning "on ice" with a message to voters that there are "five days to stop brexit". she said scotland could be pivotal to denying the conservatives a commons majority. today's other news now, and iran and the united states have

carried out a prisoner swap. the exchange is a rare sign of cooperatrion between the two countries, which have had an increasingly strained relationship in recent years. our washington correspondent, chris buckler, has more. a brief thaw in relations between the us and iran saw massoud soleimani return to tehran. it was an emotional homecoming for a university professor who was arrested in chicago a year ago, accused of violating trade sanctions. and just as he was released, an american citizen, xiyue wang, was allowed to begin his journey home from an iranianjail. i think it was a great thing for iran, i think it was great to show that we can do something. it might have been a precursor as to what can be done. the prisoner exchange marks a rare moment of cooperation between washington and tehran. only months ago, they appeared to be heading towards conflict and confrontation following attacks

on tankers in the gulf. both sides can claim success from these negotiations, even if the iranian foreign minister had angry words for america during a news conference following massoud soleimani's release. xiyue wang's family had been waiting more than three years for him to be freed. the princeton university academic was charged with spying as he carried out research in iran. since then, his family have made several appeals for him to be allowed home to his wife and son. he was barely three when my husband left home for his research. and he's now six. he's missed him for half of his life already. iran and the us may have shown some ability to compromise but the obvious tensions between the two countries have not gone away. chris buckler, bbc news, washington.

in australia, firefighters say a fire burning north of sydney is now bigger than the city itself. they're warning that it's currently too big to put out. many residents have been forced to leave their homes, as phil mercer reports. a twisting column of flame, a fire in queensland advances across dry grassland, threatening homes. the crisis in eastern australia is into its fifth week. the authorities are warning that some of the bushfires are too big to put out and will only be extinguished heavy rain. there are 100 blazes in drought—hit new south wales. half are burning out of control. residents and animals have been forced to flee as the flames bore down on their communities. so at any time, it mightjust come over this side, so we will just leave. more than 2,000 firefighters, many of them volunteers, are on the ground in new south wales. their task is exhausting and unrelenting. it's dangerous,

too. a water—bombing helicopter has crashed landed near the city of newcastle. the pilot escaped with only minor injuries. sydney is again shrouded in a toxic, smoky haze, blown in from nearby bushfires. bushfires are common in australia, but scientists believe this year they have started earlier and have been more intense due to global warming. a brutal summer lies ahead. phil mercer, bbc news, sydney. in the last few minutes, the british boxer anthony joshua has regained his three world heavyweight titles. he beat the mexican—american, andy ruiz on points in saudi arabia in the so—called clash in the dunes. straight now to our sports editor, dan roan, who's there. redemption, relief, the

fans behind me stream out of the arena. they will know that they have seen a piece of boxing history because, as you say, anthony joshua piece of boxing history because, as you say, anthonyjoshua regained all three of his heavyweight title that he lost to andy ruiz earlier this year. he becomes a member of an elite number who have managed to do it on the first attempt. we can show you some of the pictures from this evening. asjoshua you some of the pictures from this evening. as joshua made you some of the pictures from this evening. asjoshua made his way towards the ring, he would have been all too aware that it was make or break here in saudi arabia. the first heavyweight title fight the middle east has hosted. it was a fight he simply do not lose having surprisingly lost in new york earlier in the summer to the mexican andy ruiz. of course, he came in at over 20 stone, a big weight difference between the two fighters and he wanted to turn this into the slu gfest that and he wanted to turn this into the slugfest that we saw in new york which ended in such a surprising victory for him this year but he

was unable to do it. joshua booked very cleverly, safety first performance, going in on thejobjoshua and that proved decisive, building a healthy lead, he won in the end by a unanimous decision. scenes of victory at the end. joshua would have been wondering whether or not he can now go on and complete his dream to become undisputed heavyweight world champion. perhaps heavyweight world champion. perhaps he can get fights with those like tyson fury. there might be a rematch in the wake of that victory for anthonyjoshua but for now he can baskin anthonyjoshua but for now he can bask in the glory of having put his career back on track after a masterclass boxing performance. manchester city are investigating allegations of racial abuse towards manchester united players during this afternoon's derby at the etihad stadium. the club say they're working with police after videos were shared online which seemed to show

a supporter making monkey gestures towards united player fred. city say they'll ban anyone found guilty of racist abuse for life. back to the election now and our regional political correspondents have been gauging opinions in their areas. tonight it's the turn of bbc devon's jenny kumah, who's has been to the constituency of north devon. the seat was held by the liberal democrats until 2015, when it was won by the conservatives. the lib dems are hoping to win it back. north devon. coastal, rural towns and villages. there's a bit of everything in this vast constituency. on the coast is ilfracombe, once a booming seaside town. but with the rise of cheap foreign travel, it's faced decades of social and economic challenges. north devon has traditionally been a lib dem stronghold. they held the seat for more than 20 years before losing it

to the conservatives in 2015. but can they win the seat back when a majority of people here voted to leave? among them, ben — a localfisherman who tells me he'll be voting conservative. being a fisherman in ilfracombe, we've lost a lot of fishing fleets around the country. and obviously, our quota system being made by the eu, how many hundreds of thousands of miles away from where the actual fishing is coming on, and you just lose a lot of fish and a lot of knowledge through quota systems. moments from the harbour is the charity bell's place. some of the poorest communities in england live in ilfracombe and here volunteers provide hot meals for those who need it. community worker keith has voted lib dem in the past. well, it's always been a liberal democrat area.

and i think, honestly, they are more in tune with normal people. hospital charity worker gloria is worried about healthcare. the local inpatient ward closed down five years ago and some people have to travel up to 100 miles for certain treatments. we need more nurses, more doctors, so that we can get a lot of our clinics back. a lot of our people need those services. a0 minutes away is david's farm near south molton. he backed remain, but he's changed his mind on brexit — even though it could have an impact on his business. whether we can export eggs post—brexit. we won't know whether we can export some of our milk. lamb exports might be difficult. but we have got to work through it and i'm sure that, with determination, we would be able

to do that. the lib dems made a comeback in the local elections here earlier this year. but whether they can turn the tide and achieve parliamentary success will depend on what's on voters' minds this election. jenny kumah, bbc news, ilfracombe. and you can find a full list of candidates for the north devon constituency at bbc.co.uk/election. that's it from me. you can see more on all of today's stories on the bbc news channel. goodnight. there is a strong jet stream across the atlantic that is picking up deepening areas of low pressure heading towards the uk and it will be a very windy few days. the strength of the wind likely to have impact but accompanied by

heavy rain. today, we have seen this cloud spilling in from the atlantic, bringing heavy rain for the hills of western scotland and is all wrapped around an area of low pressure up to the west. at the same time as this rain is moving into the uk, the winds are strengthening, that has happened over the past few hours, and we will all get a spell wet and windy weather for a time overnight is that rain sweeps down towards the south—east. clear skies following behind and plenty of showers towards the north—west. in the north and west of scotland, gusts may be 60 mph towards the end of the night, all helping to keep those temperatures on the mild side. a windy day to come on sunday, a day of sunshine and blustery, heavy showers, not too many showers for the eastern side of england but further west they will be more frequent, merging to give longer spells of rain in northern ireland, western scotland and the north

west of england. wintry over the hills. the windy day to come on sunday, a day of sunshine and blustery, heavy showers, not too many showers for the eastern to the day as we start to see the storm getting that bit closer. it is just a squeeze on the isobars. not just across ireland but over the irish sea and into the south—west, gusts of 70 mph or more in wales and the south—west of england. that will slowly ease down a bit during monday as this ridge of high pressure comes in and the stronger winds are likely to continue for longer down the eastern coast of england and scotland through the north sea. gales here, showers for a while, they will ease off and then we will see things coming down, winds gradually easing, most places dry and sunny, chillier perhaps than cloud and patchy rain arriving in northern ireland during the afternoon. but more wet and windy weather to come. the next weather system driving in during tuesday night,

bringing heavy rain, likely to bring some squally winds as well.

hello. this is bbc news. we'll be taking a look at tomorrow morning's papers in a moment. first the headlines: the belts come back to britain. anthonyjoshua wins back his world titles, beating andy ruiz over 12 rounds in riyadh.