or about 50 pounds of the explosive tatp exposedly belong to the bombers and in this case pa nick peyton walsh has more on this. >> children screaming. is this the aftermath of a tapt bomb? officials found 15 kilograms of the explosive where an alleged bombmaker was hiding out. it's a home made explosive with a sinister nickname, motor of satan. it's sensitive to heat, hole tile and can potentially cause extensive damage. experts say it's cheap with ingredients that are easy to come by. >> 90% of the stuff we have here, you don't need a license to buy. i can go in the truck right now about half an wore away and come home with probably 90% of this. >> brussels is not the first time tatp has been traced to terrorist attacks. last november, ibrahim dead nated it as part of the paris attacks. one component, tatp. july 2005, bombs explodes throughout london. 52 dead, more than 700 injured. investigators discover the home made bombs contained tatp. september 2009, a man is arrested for plotting to bomb a new york city subway using tatp. he gets the greens he needs at a colorado beauty store, a lowe'

nick peyton walsh. >> reporter: they have shipped hard drives to the united states for further analysis. the language suggesting this must be encrypted or something they can't get into it. these laptop phobes seized during the number of raids it seems every night sints the attacks. but the key issue at this point is who was the man in white from the surveillance video from the attacks. there had ban brief moment in the respite from brussels they may have caught their man. there were suggestions in the media. faycal c could have been that individual. it turns out faycal c. is innocent. they simply don't have the evidence to continue holding him so the man in white is still at large. as the mote row bomber. that being khalid al bakraoui. and the number of clues are growing. we ourselves spoke to neighbors of the flat, the apartment where the bakraoui brothers prepared the chemicals that were part of the bombs. they described how a leak was so clumsily done that in fact the chemicals seeped down to the floor below. that is how many they actually spilled. how the key isis bomb maker visited

also with us senior international correspondent nick peyton walsh. i'll begin with you.t you bring us up to date on you are learning about the investigation. are they any closer to tracking down the two suspects that are still on the loose? >> hour by hour they are further away from that key goal. obviously finding the man in the airports with the cctv and the accomplice the metro bomber is the most urgent task. yesterday in the afternoon, a man has incorrectly and widely has been identified as the man in white was released for lack of evidence. they simply didn't have enough to hold him in the eyes of the investigation. now, that of course has led to a great lack of confidence in how they are progress. there has been a sigh of relief that maybe one of the two is in custody. it appears to mount every day. the number of clues they have. we're talking about men who had interpol against them, deported from turkey, who went on to be the bombers. a real sense of an investigation in crisis. >> ryan, we look at what is happening in the last few days. we have seen all of these r