bridget kendall, bbc news. >> it's certainly intriguing. our world affairs correspondent nick charles is with me. you've been having a sort of study at the video. can we say for certain he's in kobane? >> it's very difficult, david. one of the things one shouldn't be surprised about with i.s. videos is that even the most grim and gruesome of them, we've all said one of the hallmarks of them has been the very high production values and capabilities that are being put into them and this is another one of those, albeit that it is in many other ways even more extraordinary what we actually see. from looking at it very closely, from having been focused on kobane for a long time now, one can say that a lot of the footage does look like kobane. there are some telltale landmarks there. some of the footage does look like it is him in kobane. some of it's far from clear where that is him in kobane. and as i say, given possibly some of the video techniques that are out there, one has to raise questions. one has to raise questions about some of the thi

bridget kendall has been studying the video. >> hello, i'm john campley, and today we're in the city of kobane on the syrian-turkish border. >> reporter: he may look like a war reporter, but in fact, he's a hostage, being held by the militants who call themselves islamic state. >> for a month now, the soldiers of islamic state have been besieging this key kurdish city. and despeet continual american air strikes, which so far have cost nearly half a billion dollars in total, they have pushed deep into the heart of the city. >> reporter: the propaganda message seems clear, denial that american bombardments of kobane has succeeded in pushing the militants back. but it's what john campley tells about himself is significant. compare how he looked in previous videos. very much a prisoner. pale-faced with little to suggest when and where the filming was done. it's not clear if he knows that his father, who made an appeal to his son's captors from his hospital dead, has recently died. four other western captives as well as numerous other prisoners held by these ruthless militants have been b