The Scottish Government has declined a request from US Senators that Justice Secretary Kenny MacAskill appear at a hearing on the Lockerbie controversy.
The US Senate Committee on Foreign Relations asked for Mr MacAskill, who gave permission for the release of the man convicted of the bombing, to attend the meeting next week.
The Scottish Government said it had formally declined the request and also turned down a request that Scottish Prison Service health boss Dr Andrew Fraser appear.
Libyan Abdelbaset al-Megrahi was released from Greenock jail last August on compassionate grounds, having been given three months to live. He is still alive and living with his family in the Libyan capital, Tripoli.
Megrahi is the only man to have been convicted of the Lockerbie atrocity which killed 270 people in the bombing of Pan Am flight 103 on December 21 1988.
David Cameron's first visit to Washington as Prime Minister was overshadowed earlier this week by the row over his release, with US senators suspicious that oil giant BP may have had a hand in the affair.
Scotland First Minister Alex Salmond wrote to the committee chairman John Kerry on Wednesday, making clear that the Scottish Government made the decision to free al-Megrahi on compassionate grounds and had received no representations from BP on the matter.
A Scottish Government spokesman said: "The First Minister wrote to Senator Kerry on Wednesday providing comprehensive information and assistance, which is the appropriate nature of Scottish Government involvement in the Senate Committee's hearing next week."
The spokesman added: "The focus of the Senators' concern has been any role played by BP in decisions on al-Megrahi, and we have stated categorically to Senator Kerry that there was no contact of any kind between the Scottish Government and BP.
"In addition to the extensive information already provided, we have written to Senator Kerry again today and offered to answer any additional questions in advance of the hearing, and we would also be very happy to answer formally and in writing any more questions that may arise from the hearing itself."