al-megrahi stayed behind bars. and the quest for the truth goes on. john: this case is very polarized. i worked as a researcher with megrahi's lawyers. i've been involved in the case for about 30 years. there's very much two different camps. one camp believes that justice was done at camp zeist, to the extent that megrahi was convicted. and then there are others who are very skeptical of the megrahi conviction. in fact, believe that he was wrongly convicted and believe that the suspects actually lie outside of libya, in iran and a radical palestinian group. interviewer: do you feel megrahi is guilty? that's a re... that's a very difficult question to answer. i have a lot of unease about information that i know is out there but i'm not able to get sight of it for reasons of national security. until access to those can be gained, i think the controversy will continue. so, for many people after the trial there are even more questions, rather than less. (church bell tolls) interviewer this is the infamous filing cabinet you were talking about? that's the

his friend was abdelbaset al-megrahi who apparently was an intelligence officer. based on the artists' rendition, megrahi looked like the person who had bought the clothing found in and around the suitcase containing the bomb. but we needed more evidence, you know. there's still more work to be done. everybody in our government wanted to find out who did this, and as a result of that, the cia did something, and i won't say it's never happened, but i will say it's a rarity. they offered up one of their sources to the fbi. they had a source in malta - majid giaka. they said that he was a double agent, he had worked at the airport, but he had left and gone back to libya, and they were trying to find him. the fbi codename for him was puzzle piece, because he became so critical, he was a piece of the puzzle. so, he volunteered himself. we call them "walk-ins". he walked into the embassy in malta, claimed he was affiliated with the libyan intelligence. he worked for libyan arab airlines. we knew it was common practice for the libyan intelligence service to use libyan ar