Megrahi's welcome in Libya created outrage around the world
The son of Libyan leader Colonel Gaddafi has insisted no deals were linked to the compassionate release of the convicted Lockerbie bomber.
But Saif al Islam Gaddafi said earlier talks with the UK government about a possible prisoner agreement with Libya always revolved around trade.
Abdelbaset Ali al-Megrahi was released from jail to die and returned to a jubilant welcome in Libya last week.
Saif Gaddafi told The Herald newspaper this was "no official celebration".
A total of 270 people were killed when a Pan Am jet exploded over the Scottish town of Lockerbie in 1988.
Megrahi was freed after the Scottish government considered applications to transfer him to Libya or to release him on compassionate grounds, due to his terminal prostate cancer.
Speaking at his home near Tripoli, Saif Gaddafi said the "deal in the desert" more than two years ago - which saw an agreement signed between Tony Blair and Libya allowing prisoner transfers - specifically targeted Megrahi, but he said the bomber's name was never mentioned.
He told The Herald: "It was part of the bargaining deal with the UK. When Blair came here we signed the agreement. We didn't mention Mr Megrahi.
"We signed an oil deal at the same time. The commerce and politics and deals were all with the PTA [prisoner transfer agreement]."
Prime Minister Gordon Brown has been urged to disclose details of trade deals negotiated with Libya after it emerged that three ministers visited the country in the 15 months leading up to the release of Megrahi.
Last week, Saif Gaddafi faced criticism for suggesting that in all commercial contracts for oil and gas with the UK Megrahi's transfer was on the "negotiating table".
He told The Herald he denied there had been a quid pro quo and said his comments had been misunderstood partly because people did not understand the difference between the PTA and compassionate release.
He said it had touched the minds of many Libyan people and that was why they were flying Scottish flags and claimed many families of Scottish victims had written to him saying they supported Scottish Justice Minister Kenny MacAskill's decision.
Lockerbie was "history" and the next step was "fruitful and productive business" with Edinburgh and London, he added.
He also confirmed that Megrahi would not be taking part in next week's 40th anniversary celebrations of Colonel Gaddafi coming to power.