Image caption Mr Salmond said the documents would vindicate the Scottish government

The Scottish first minister has called on the UK and US governments to publish all of their documents relating to the release of the Lockerbie bomber.

The Sunday Times claimed to have seen a letter from the US administration to the Scottish government before the release of Abdelbaset Ali al-Megrahi.

It said the US government did not want Megrahi released from prison.

But it said a compassionate release would be "preferable" to transferring Megrahi to a jail in Libya.

Alex Salmond said the documents would "vindicate" the Scottish government.

Megrahi was jailed after being convicted by a Scottish court of murdering 270 people by blowing up Pan Am flight 103 over the town of Lockerbie, in south west Scotland, in 1988.

The majority of those who died were US citizens.

He was released in August last year after doctors said he was dying of prostate cancer and had three months to live.

Speaking on Sky News, Mr Salmond emphasised that the Scottish government had made public all of its own documents relating to the release of Megrahi.

He said the UK and US governments had refused to grant permission for some of the correspondence they had with the Scottish government ahead of Megrahi's release to be published.

Mr Salmond did not explicitly confirm the existence of the letter referred to in the Sunday Times.

Senate committee

But he said: "I think that a fair description of the American government's position is they didn't want al-Megrahi to be released.

"However, if he was to be released, they thought it was far preferable for compassionate release as opposed to the prisoner transfer agreement.

"Presumably the reason that they were so opposed to the prisoner transfer agreement is on roughly the same grounds as the Scottish government had for opposing that agreement - because it was signed initially at the same time as an oil deal was being signed in the famous Deal in the Desert."

The US ambassador to the UK, Louis Susman, said the US was examining whether its correspondence over the issue could be released but refused to be drawn on the reported memo..

Image caption Senators want to investigate claims oil giant BP lobbied for the Lockerbie bomber's release

The ambassador added: "It is quite clear that the US government was strongly against the release of Megrahi.

"We had a mutual understanding with the British government that if he was tried and convicted he would serve his entire sentence in Scotland.

"The fact that the justice minister made a decision on compassionate grounds to release him was something we were not in favour of.

"We obviously had conversations with them in which we strongly objected to any type of release."

Oil firm BP admitted earlier this month it had lobbied the UK government in late 2007 to conclude the prisoner transfer agreement with Libya as it feared any further delay would damage its commercial interests in the region, including the ratification by the Libyan government of BP's exploration agreement.

Mr Salmond repeated that the Scottish government had no contact with BP in the build up to Megrahi's release on compassionate grounds.

Last week, President Barack Obama told a White House press conference that the US had been "surprised, disappointed and angry" about Megrahi being released.

The Scottish government has refused to send any representatives to a US Senate committee hearing into Megrahi's release, which is due to be held on Thursday.

The committee, which is to be chaired by New Jersey Senator Robert Menendez, wants to establish whether oil giant BP influenced the decision.

Mr Menendez is also understood to have requested that the correspondence between the Scottish and US governments be published.

Former UK Home Secretary Jack Straw has also declined an invitation to appear before the committee.