Moammer Gaddafi personally ordered the Lockerbie bombing in 1988, former justice minister Mustapha Abdeljalil told Swedish daily Expressen, the paper reported.
The claims came as Gaddafi's regime appeared to be crumbling around him.
Reports said up to 1000 people could have been killed in the ongoing violence, amid news that the country was effectively divided.
Anti-government forces were in control of cities in the eastern half of the city, while there were reports of marauding bands of mercenaries cruising the streets to crush protesters and keep Western towns such as Tripoli in Gaddafi's hands.
Gaddafi 'ordered Lockerbie'
"I have proof that Kadhafi gave the order on Lockerbie," said the minister, who stepped down Monday to protest the ongoing violence in Libya, AFP reported.
Libyan national Abdelbaset Ali Mohmet al-Megrahi was in 2001 convicted of the bombing of Pan AM Flight 103 over the Scottish town of Lockerbie on December 21, 1988 that killed 270 people, most of them Americans.
But Scottish authorities, who have power over their own judicial affairs, released Megrahi, 58, on compassionate grounds in August 2009 after doctors said he was suffering from terminal cancer and had three months to live.
His release and subsequent hero's return to Tripoli drew a furious response from many, and outrage in the United States has been stoked by the fact that he remains alive almost a year and a half after his release.
International pressure has been mounting on Libya, as both Libyan nationals and foreign citizens fled the country.
