From the Times:

LONDON — The oil giant BP faced a new furor on Thursday as it confirmed that it had lobbied the British government to conclude a prisoner-transfer agreement that the Libyan government wanted to secure the release of the only person ever convicted for the 1988 Lockerbie airliner bombing over Scotland, which killed 270 people, most of them Americans.
The admission came after American legislators, grappling with the controversy over the company’s disastrous Gulf of Mexico oil spill, called for an investigation into BP’s actions in the case of the freed man, Abdel Basset Ali al-Megrahi.
The former Libyan intelligence agent was released and allowed to return to Libya last August after doctors advised the Scottish government that he was likely to die within three months of advanced prostate cancer. But nearly a year later, he remains alive, and free, in the Libyan capital, Tripoli.
BP’s statement on Thursday repeated earlier acknowledgments that it had promoted the transfer agreement to protect a $900 million offshore oil-and-gas exploration deal off Libya’s Mediterranean coast. The British justice minister at the time, Jack Straw, admitted shortly after Mr. Megrahi was repatriated and freed that the BP deal was a consideration in the government’s review of his case.
In the end, Mr. Megrahi was not released under the prisoner transfer agreement. Instead, to the consternation of the Obama administration, and of many of the victims’ families, the Scottish government released him in August 2009 under provisions in Scottish law that allow for a prisoner’s sentence to be commuted on humanitarian grounds, because Mr. Megrahi had terminal prostate cancer. That freed him from serving any further prison time in Libya, as he would have had to do under the transfer pact.

The four Senate Democrats representing New York and New Jersey have called for the State Department to investigate the matter.