Senators want inquiry into Megrahi release

His longevity was earlier this week described as "embarrassing" by Professor Karol Sikora, who was paid by the Libyan authorities to assess him. His release, eight years into a life sentence, angered the United States, particularly as many Americans were on board the New York-bound flight.

The letter from both New York senators, Kirsten Gillibrand and Charles Schumer, and their New Jersey counterparts, Frank Lautenberg and Robert Menendez, to the UK's ambassador to the US, Nigel Sheinwald, calls on the British government to conduct a full investigation into the release decision.

Senator Schumer said: "There is clear reason to believe that this terrorist was released based on false information about his health.

"This is especially galling to those of us who believed he shouldn't have been released even if it had been true that his death was imminent."

Senator Lautenberg added: "This terrorist belongs in prison and these allegations must be investigated promptly."

The senators cite allegations that the bomber's release was motivated by business and political factors.

BP is to begin deep-water drilling off Libya's coast next month, as part of a programme which could reap the oil giant approximately 13 billion.

The senators wrote: "The doctor responsible for the key medical opinion has told the media that not only could Mr al-Megrahi live another ten years, but that the Libyan government had commissioned the doctor to make his assessment, expressly because the Libyan government hoped for a three-month prognosis. This is outrageous.

"These newly revealed details threaten to undermine public trust in due process and justice for the victims of terrorism.

"Unfortunately, allegations are circulating in the media that the release may have been motivated by political and business considerations.

"If true, this would significantly undermine the ability of countries that practice the rule of law to bring future terrorists to justice."

The letter was passed to the Scottish Government by the British Embassy in Washington.

A Scottish Government spokeswoman said: "Mr al-Megrahi has terminal cancer.

"The decision to release him on compassionate grounds was based on the recommendations of the prison governor and Parole Board and advice from the Director of Health at the Scottish Prison Service who drew on expert advice from a range of specialists.

"These specialists did not include Dr Karol Sikora and Dr Sikora's advice formed no part of any considerations by the Justice Secretary."