LONDON (AFP)--Britain's Foreign Secretary William Hague said Saturday that BP played no part in securing the release of the Lockerbie bomber from prison, while calling the decision to free him "wrong and misguided". Hague's comments came in a letter to John Kerry, the chairman of the U.S. Senate's Foreign Relations Committee, which is Thursday holding a hearing into the release of Libyan Abdelbaset Ali Mohment al-Megrahi from a Scottish jail. Megrahi, the only person convicted over the 1988 bombing of an airliner which killed 270 people, was freed by the Scottish government last year on compassionate grounds due to his terminal cancer. Hague's letter is the latest attempt by British politicians to offer reassurance that British-based BP, under intense pressure in the U.S. over the Gulf of Mexico oil spill, did not push for his release to pave the way for a lucrative oil deal with Libya. The issue repeatedly cropped up during Prime Minister David Cameron's visit to the White House this week and Hague has previously written to U.S. Secretary of State Hillary Clinton about it. "I believe we have a responsibility to address the unsubstantiated rumours that there was some sort of conspiracy involving BP which led to Mr Megrahi's release," Hague wrote to Kerry in a letter released by the Foreign Office. He said there had been "legitimate" contacts on at least five occasions between oil giant BP and senior British officials over a prisoner transfer agreement between Britain and Libya which was signed in 2008. But Megrahi was not released under this, instead being freed on compassionate grounds by the Scottish government. "There is no evidence that corroborates in any way the allegation of BP's involvement in the Scottish Executive's entirely separate decision to release Mr. Megrahi on compassionate grounds in 2009, nor any suggestion that the Scottish Executive decided to release him on compassionate grounds in order to facilitate oil deals for BP," Hague wrote. Meanwhile Scottish Justice Secretary Kenny MacAskill, who made the decision to free Megrahi, defended his decision not to go to Washington to give evidence to the U.S. Senate committee. "I'm elected by the people of Scotland and accountable to the people of Scotland," he told the BBC. "This matter is a matter of Scottish jurisdiction." Scotland forms part of Britain, but under its devolved administration has control over its own justice matters. BP Chief Executive Tony Hayward has been asked to attend Thursday's committee hearing. The firm has confirmed it will send a representative. (END) Dow Jones Newswires July 24, 2010 14:27 ET (18:27 GMT)