Former prime minister Tony Blair twice visited Libya for talks with Colonel Muammar Gaddafi in the months leading up to the release of the Lockerbie bomber, it has been disclosed.

The Sunday Telegraph reported that documents discovered in Tripoli showed that the ousted dictator had arranged to fly Mr Blair on his private jet for meetings in June 2008 and April 2009.

The talks came at a time when Libya was threatening to sever all commercial links with Britain if Abdelbaset al-Megrahi was not released from the Scottish prison where he was being held for the 1988 bombing of Pan Am flight 103.

A spokesman for Mr Blair acknowledged that the Libyans had raised the issue of Megrahi's release but said that the former premier had simply told them that it was a matter for the Scottish Executive. The spokesman added that there had been no "commercial or business element" to the meetings.

However, the latest disclosure it likely to add to pressure for Mr Blair to make public the full extent of his dealings with Gaddafi since leaving Downing Street in 2007.

The Sunday Telegraph said that the documents showed that in both 2008 and 2009, Mr Blair negotiated to fly to Tripoli from Sierra Leone in west Africa in a jet provided by Gaddafi.

The first letter, sent on notepaper headed Office of the Quartet Representative - Mr Blair's title as Middle East peace envoy - was written by Gavin Mackay in Mr Blair's London office to the Libyan ambassador to the UK and is dated June 2 2008. It stated: "Let me begin my (sic) saying that Mr Blair is delighted that The Leader is likely to be able to see him during the afternoon of 10 June and he is most grateful that the Libyan authorities have kindly offered an aircraft to take him from Freetown to Tripoli and back to London."

Details of the 2009 meeting are contained in an exchange of emails between Victoria Gould, who was Mr Blair's events organiser, and Sir Vincent Fean, the former British ambassador to Libya. Miss Gould wrote to Sir Vincent on March 31 to say an audience with Gaddafi was "looking positive". She added: "If we were able to stay at the Residence I know TB would be really grateful (as would we all)."

A spokesman for Mr Blair said: "As we have made clear many times before, Tony Blair has never had any role, either formal or informal, paid or unpaid, with the Libyan Investment Authority or the government of Libya and he has no commercial relationship with any Libyan company or entity.

"The subjects of the conversations during Mr Blair's occasional visits was primarily Africa, as Libya was for a time head of the African Union; but also the Middle East and how Libya should reform and open up."