Blair, who left office in June 2007, used a Libyan regime jet to visit Gaddafi in June 2008 and April 2009, the broadsheet said, citing documents discovered in Tripoli since Gaddafi was ousted from power.
Blair played a major role in trying to bring Gaddafi in from the cold in exchange for giving up his nuclear weapons programme and first visited him in March 2004 in what was dubbed the “deal in the desert”.
A spokesman for Blair acknowledged that the visits took place and that the Libyans had raised the issue of Abdelbaset Ali Mohmet al-Megrahi but the former premier simply told them that it was a matter for the Scottish authorities.
Megrahi is the only man convicted over the December 1988 bombing of Pan Am flight 103, which killed 270 people, mostly Americans, when it exploded over the Scottish town of Lockerbie.
Megrahi, who has terminal cancer, was said to be only three months from death when he was freed from a Scottish jail on compassionate grounds on August 20, 2009.
The Telegraph disclosure is likely to add to pressure for Blair to make public the full extent of his dealings with Kadhafi since leaving Downing Street.
The Sunday paper said that the documents showed that in both 2008 and 2009, Blair negotiated to fly to Tripoli from Sierra Leone in a jet provided by Kadhafi.
The documents also showed that Blair had a further private meeting with Kadhafi in June 2010.
The Sunday Telegraph said the visits raised concerns of possible conflicts of interest between Blair’s roles as a Middle East peace envoy, a business consultant and a philanthropist.
A spokesman for the ex-premier said: “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.
“Of course the Libyans, as they always did, raised Megrahi. Mr Blair explained, as he always did, in office and out of it, that it was not a decision for the UK government but for the Scottish executive.
“No business deals of any nature were discussed. At the time, governments around the world were engaging with Libya. Kadhafi was received in several European capitals including Brussels, Rome and Paris.
“There was therefore at that time no reason whatsoever for not continuing to engage with him, especially since Mr Blair in office had been responsible for getting Kadhafi to give up his chemical and nuclear weapons programme and renounce terrorism.”
A review released in February found that the British government did “all it could” to help Libya in pursuing Megrahi’s freedom, fearing that “UK interests would be damaged” otherwise.