BP's role in the release of the Lockerbie bomber from a Scottish prison is being questioned in a letter to the Senate Foreign Relations Committee by Sen. Frank Lautenberg, who is requesting an investigation into the oil company's success in securing a drilling contract in Libya.

Abdel Basset al-Megrahi, a Libyan intelligence agent convicted in the 1988 bombing of Pan Am flight 103, won early release from prison last year after a doctor testified that he was near death and it would be compassionate to let him die a free man. But there are suggestions that Megrahi, who was given just weeks to live but is still alive and kicking, may have been the linchpin in BP's efforts to secure drilling rights in the Gulf of Sidra. 

"The prospect that oil contracts between BP and the government of Libya may have affected the release, as well as new questions about the veracity of medical reports detailing Mr. Megrahi’s health at the time, are disturbing developments that demand the attention of Congress, Lautenberg, D-N.J., wrote to Sens. John Kerry, D-Mass., and Richard Lugar, R-Ind., the co-chairmen of the Foreign Relations Committee.

The explosion of the plane over Lockerbie, Scotland, killed 270 people, including 189 Americans. The same doctor who called for his release now says Megrahi could live for years. 

The U.K.-based BP, which is responsible for the oil spill that has been gushing into the Gulf of Mexico for 85, admitted that in 2007 it raised concern that a "prisoner transfer agreement with the Libyan government might hurt" the oil deal, according to Lautenberg. 

Megrahi originally had not been part of the prisoner transfer, but former British Secretary of State for Justice Jack Straw later cited "overwhelming interests for the United Kingdom" in including Megrahi. 

BP could earn as much as $20 billion from the deal with Libya, set to begin next month. 

"It is shocking to even contemplate that BP is profiting from the release of a terrorist with the blood of 189 Americans on his hands," Lautenberg wrote. "The families of the victims of Pan Am flight 103 deserve to know whether justice took a back seat to commercial interests in this case."

Click here to read the Lautenberg letter.

This is not the first time Lautenberg has questioned Megrahi's release last August. In September he questioned whether the agreement was influenced by oil contracts between BP and the government of Libya. 

Last week, Lautenberg, Sen. Bob Menendez, D-N.J., and New York Democratic Sens. Kirsten Gillibrand and Chuck Schumer urged the British government to probe the Scottish court's decision to release Megrahi.