By Keith Weir
LONDON (Reuters) - Scottish leader Alex Salmond has broken off correspondence with four U.S. senators over the release of the Lockerbie bomber in frustration at their refusal to accept his government's explanation of events.
Scottish authorities freed Abdel Basset al-Megrahi in August of last year on compassionate grounds because they thought he had only three months to live with prostate cancer.
Megrahi, 58, is still alive in Tripoli and his survival has fuelled U.S. unease over the decision to free him. American politicians have questioned whether oil giant BP lobbied Scotland for his release.
BP and Scottish ministers have denied the accusations which risked further tarnishing BP's reputation after the Gulf of Mexico oil spill.
"There is no evidence, circumstantial or otherwise, that links decisions made by the Scottish Government to commercial interests," Salmond wrote to U.S. Senators Robert Menendez, Kirsten Gillibrand, Frank Lautenberg and Charles Schumer.
"Indeed, the substantial evidence that does exist shows that the Scottish Government specifically rejected any attempt to bring commercial or business considerations into the decision-making process on compassionate release, and stated that decisions would be based on judicial grounds alone," he added in a letter obtained by Reuters.
Megrahi was sentenced to life in prison in 2001 for his part in blowing up New York-bound Pan Am flight 103 in December 1988, killing 259 people on board and 11 people on the ground in the Scottish town of Lockerbie.
One-hundred and eighty nine of the victims were Americans.
The U.S. senators sought to hold a hearing earlier this year on whether BP had influenced the release of Megrahi as it sought contracts with Libya, an oil and gas producer. However, a number of British witnesses declined to testify.
A Scottish government spokesman said representatives of the U.S. senators were expected to visit Scotland this week. Scottish officials would be prepared to meet them to provide background information but not formal evidence, Salmond said.
"As your recent letters raise no new issues of substance, I am now drawing a line under this correspondence," Salmond said in his letter, date September 10.
BP has confirmed it lobbied the British government in 2007 over the conclusion of a Prisoner Transfer Agreement (PTA) with Libya because it was concerned a slow resolution would impact an offshore drilling deal with the Libyans.
However, the Scottish authorities, responsible for judicial decisions independent of the British parliament, have pointed out that the PTA played no role in Megrahi's eventual release.
"Your letter of 19 August goes on to conflate the process of application for prisoner transfer with the quite separate process of applying for compassionate release," Salmond wrote.
"I have explained these separate processes at some length in our previous correspondence. It is of great concern that, despite these explanations, you seem unable or unwilling to understand the nature of these separate legal processes."