Scottish Justice Minister Kenny MacAskill on Aug. 20 released Megrahi, the lone suspect in the 1988 bombing of Pan Am Flight 103, on compassionate terms as the former Libyan intelligence officer suffers from terminal cancer.
Allegations surfaced last year that the Megrahi release was part of a prisoner transfer agreement between the British government and Tripoli. Oil was raised as a key issue as well.
The bombing of Pan Am Flight 103 killed 259 people on board and 11 people on the ground.
Megrahi, The Times of London reports, is working on a documentary that will allegedly highlight his attempts to clear his name. The Libyan gave up on his legal claim in August when he was returned to Tripoli.
Scottish opposition spokesman Bill Aitken complained the government needs to come clean on the details surrounding his release.
"It is now nine months since Britain's worst mass murderer returned to Tripoli to a hero's welcome," the Times quoted him as saying. "The Scottish National Party government has yet to come clean and produce the evidence that set him free."
MacAskill prior to his decision said medical records suggested Megrahi had less than three months to live.