Lockerbie bomber: Straw declines senators' invitation

The former Justice Secretary said he could not help the inquiry because he had "absolutely nothing to do" with the decision to free Abdelbaset al-Megrahi on compassionate grounds last August.

His refusal came after Scottish Justice Secretary Kenny MacAskill also confirmed he would also not be testifying as he had "no information to provide" on alleged lobbying by BP to secure an oil deal with Libya.

In a letter to Senator Robert Menendez, of the Foreign Relations Committee, Mr Straw said: "It was, as I understand he has already explained, Mr Kenny MacAskill, the Scottish Justice Secretary who last August made the decision to release Mr al-Megrahi on compassionate, medical grounds.

"I had absolutely nothing to do with that decision. I saw no papers about it, and was not consulted about it.Indeed I was on holiday at the time and only learnt about it from an item on the BBC News website.

"I believe that Mr MacAskill has confirmed that the decision was one taken entirely on medical grounds, without involvement from the UK Government, and without pressures from BP.

"It follows from this that I do not see how I could help your committee 'understand several questions still lingering from this decision', as I did not make it, nor have any other locus in it.

"You will therefore excuse me if I do not accept your committee's kind invitation."

Mr Straw also insisted that, although he helped negotiate a Prisoner Transfer Agreement between the UK and Libya, that had "no bearing" because it was not used in Megrahi's case.

The senators wanted Mr Straw, Mr MacAskill and BP chief executive Tony Hayward to help them investigate suspicions that oil giant BP may have had a hand in the release of Megrahi.

Later, Congressman Eliot Engel, who has campaigned on the case, said he was "very disappointed" by the decision.