In case you thought BP’s PR problems couldn’t get any worse…

BP is taking it on the chin over Libya’s apparent snookering of Scotland in the prison release of Abdel Basset Ali al-Megrahi, the only person convicted of the 1988 crash of Pan-Am 103 over Lockerbie, Scotland, which killed 270 people. Sen. Frank Lautenberg has asked for a Senate investigation of whether BP improperly influenced the British government to help arrange for Megrahi’s release.

Megrahi was released from a Scottish prison last summer. A doctor said that Megrahi had only a month to live because of prostate cancer, and the Scottish government let him go under a law allowing compassionate release of prisoners with less than three months to live. Since then, the doctor has said that "there was always a chance he could live 10 years, 20 years."

BP acknowledged last year that in 2007, Mark Allen, one of its paid advisers, had spoken with then-British Justice Secretary Jack Straw about a slowdown in BP’s efforts to proceed with offshore drilling in Libya, the Wall Street Journal has reported. The drilling was threatened, Allen told Straw, because of a stalled agreement between the countries that would allow prisoners in Britain to be released to Libyan custody. Megrahi’s name wasn’t in the agreement, but everyone knew whose release was intended.

That agreement did not go through. But meanwhile Scotland made its determination and freed Megrahi.

As the New York Times‘ Robert Mackey has written, doubt has been cast on Megrahi’s guilt.