Sens. Kirsten Gillibrand (D-N.Y.) and Robert Menendez (D-N.J.) repeated Monday that pressure from BP might have led to the early release of convicted Lockerbie bomber Abdelbasset al-Megrahi from prison.
They also entreated British, Scottish and BP officials to testify at an upcoming Senate hearing on the matter.
Menendez later announced that Tony Hayward, BP's outgoing chief executive, would not attend the hearing.
"The bottom line is that we need to hear from BP officials at the highest levels who had significant contact with both the Libyan and British governments," Menendez said in a statement.
Scottish Justice Minister Kenny MacAskill, who made the decision to free al-Megrahi, and former British Justice Secretary Jack Straw have also declined to appear.
A potential link between BP and al-Megrahi's return to Libya has been debated since fall 2009, but gained attention in the wake of the Deepwater Horizon oil spill in the Gulf of Mexico. Critics implicate the oil giant in the decision circumstantially, saying it lobbied for al-Megrahi's release to safeguard a $900 million oil exploration deal finalized with Libya in 2007.
Al-Megrahi was imprisoned in 2001 for the 1988 bombing of Pan Am Flight 103, which killed 270 people when it exploded over Lockerbie, Scotland. A Libyan citizen, he was repatriated by Scottish authorities in August 2009 on medical grounds, but aroused suspicion when he was reported alive nine months after Scottish authorities said he was near death.
“The abundance of incredible coincidences surrounding al-Megrahi's release deserves a real, open, transparent hearing. Full information regarding the most dubious aspects of a decision to release him should be made public,” Menendez said at a joint press conference with Gillibrand on Monday in Times Square.
Senators from New York and New Jersey have taken a particular interest in the case because many of the victims of the bombing were from the two states. Both Menendez and Gillibrand also sit on the Senate Foreign Relations Committee.
In her remarks Monday, Gillibrand called attention to a letter sent by Lord David Trefgarne, chairman of the Libyan British Business Council, to MacAskill in July 2009, urging him to release Al-Megrahi via prisoner-transfer agreement or using the justification of "compassionate grounds" permitted by Scottish law.
The senator later distributed a scanned copy via Twitter.
“Speed is of the essence principally for humanitarian reasons," writes Trefgarne, "but also because of the shadow which may otherwise fall over UK-Libyan relations — and especially the interests of LBBC Scottish members and indeed others."
Since the letter originally surfaced in September 2009, MacAskill has denied that economic or political interests influenced his decision.
BP confirmed Sunday it would begin drilling in Libya before mid-August. The Senate Foreign Relations Committee hearing, to be chaired by Menendez, is scheduled for Thursday.