he worked for libyan arab airlines. we knew it was common practice for the libyan intelligence service to use libyan arab airlines as a cover office for their operations. phil: this is the old luqa airport. investigation determined that it was here that the bomb bag... was actually put on the air malta flight to frankfurt... ..and then was transferred to the pan am 103 flight out of heathrow that blew up over lockerbie. puzzle piece was working here at luqa airport in the luggage area. the cia started looking at his reporting. which was saying that, around december of 1988, he actually saw both fhimah and megrahi coming into this airport here... ..with a suitcase. and that double agent became very, very important to us in the case. i get a phone call telling me that cia the found the double agent, majid giaka, he's on a boat, and they're bringing him to a us ship of some kind to be interviewed. got on a helicopter, we were flown out to a ship in the mediterranean, international waters. and i'm anticipating a very aggress

phil: as far as fhimah was concerned, he was the libyan arab airlines manager in malta. fhimah supposedly provided him with a luggage tag, that megrahi put on a suitcase aboard a flight to frankfurt, to go on to london and pan am 103. megrahi couldn't have got that suitcase into the system without fhimah's help. reporter: the prosecution admits its case is entirely circumstantial, but claims it is tight enough to prove murder beyond reasonable doubt. nic: however, some of the evidence was contentious. bollier appeared to recant his previous testimony. now he's not so sure a fragment of circuit board was from the timers he said he sold to the libyan intelligence service. he just seemed untrustworthy. tony gauci, the man who had a clothing store in malta, is significant, because he is the one who can identify megrahi. but he had changing recollections of the suspect. his testimony just didn't seem to stand up. phil: but we also came up with critical evidence from a double agent working at the airport. reporter: abdul majid giaka is the super-grass billed as the lockerbie t