Megrahi (left) was greeted by Colonel Gaddafi's son Seif al-Islam in Tripoli
The man convicted of the Lockerbie bombing has backed calls for a public inquiry into the atrocity.
Speaking to Scotland's The Herald newspaper from his home in the Libyan capital, Abdelbaset Ali al-Megrahi said he was determined to clear his name.
He also said an inquiry would help families of the victims know the truth.
Megrahi, who is suffering from terminal prostate cancer, was released from Greenock Prison in Scotland last week on compassionate grounds.
He returned to a hero's welcome in Libya after serving eight years of a minimum 27 years sentence for murdering 270 people in the December 1988 bombing of Pan Am 103 over the town of Lockerbie, in southern Scotland. The scenes prompted international condemnation.
The Herald quoted Megrahi as saying he would help Dr Jim Swire, whose 23-year-old daughter Flora died in the disaster and who has frequently called for a full public inquiry, by handing over all the documents in his possession.
In his first interview since being released, Megrahi told The Herald: "I support the issue of a public inquiry if it can be agreed.
"In my view, it is unfair to the victim's families that this has not been heard. It would help them to know the truth. The truth never dies. If the UK guaranteed it, I would be very supportive."
But Megrahi said he believed the UK government would avoid a public inquiry as it would cost a lot of money and also "show how much the Americans have been involved".
He said he dropped his appeal in the Scottish courts because he knew he would not live to see the outcome and was desperate to see his family, and insisted there was no pressure from Libyan or Scottish authorities.
And he made scathing comments about the Scottish legal system, but said he was impressed by Justice Secretary Kenny MacAskill during their meeting at Greenock Prison, describing him as "very decent".
Megrahi said his priority was now to spend time with his five children.
Lucy Adams, chief reporter of The Herald, told BBC News that Megrahi had looked "incredibly ill and weak" during her meeting with him, but had clearly been anxious for a public inquiry to be held.
Ms Adams said: "I think perhaps for those who are convinced of his guilt it seems interesting that he would back that [an inquiry] and he would hand over the papers he has and the documents he has.
"That seems quite an interesting position from his point of view, because that would indicate he has nothing to hide."
Ms Adams said Megrahi had been interviewed in his large villa in Tripoli while he was lying on a "hospital-style bed" in his lounge.
She added: "He was surrounded by his family, his children and other relatives, and he seemed incredibly weak and frail. He spent much of the time coughing and having to pause, but seemed determined to talk about his case and the fact that in his opinion, while he will die soon, he said the truth will never die."
"He is currently writing an autobiography in which he hopes to convince people of his innocence. He has documents which have not yet been disclosed to the public, and documents that were being prepared for his appeal which he dropped last week as part of his hopes for returning to Tripoli."
The row over Mr MacAskill's decision to release Megrahi on compassionate grounds intensified on Friday when an ICM Research poll for BBC News said 60% of those questioned thought Mr MacAskill was wrong to release Megrahi, and 57% thought he should have stayed in prison until he died.
Thirty-two per cent said Mr MacAskill was right, 7% did not know, and 1% would not say.
The telephone poll of 1,005 adults took place on Wednesday and Thursday.