Campaigners claim a former Scottish minister has called into question the conviction of the only man found guilty of the Lockerbie bombing.

Former Justice Secretary Kenny MacAskill controversially released Abdelbaset Ali Mohmed al-Megrahi on compassionate grounds after he was diagnosed with cancer.

But in a new book Mr MacAskill appears to dismiss crucial evidence that helped to convict Mr Megrahi.

He writes that he does not believe the claim he bought clothes in a store in Malta that were packed around the bomb.

He maintains, however. that Mr Megrahi played a role.

All 259 people on board and 11 on the ground where killed when a Pan-Am airliner exploded over Lockerbie in 1988.

James Robertson, of the Justice for Megrahi campaign group, said that MacAskill’s comments raised serious questions.

He said: “The most interesting thing in all this is that Kenny MacAskill has said that he does not believe that Megrahi was the man who bought those clothes.

"But this calls into account the whole Camp Zeist judgement and it would mean that Megrahi could not have possibly been behind the bombing.

“As Justice minister Kenny MacAskill repeatedly stuck to the line that he had no doubt Megrahi was guilty, but now appears to be saying the opposite.

“Alex Salmond also stuck to this line, and the Justice for Megrahi campaign will be asking if what was said in public was the same as was said in private.”

Meanwhile, Scottish Liberal Democrat leader Willie Rennie has called on the Scottish Government to make an urgent statement on other claims in the book.

He called for a response to Mr MacAskill’s claims that he and Alex Salmond attempted to cut their own deal over Mr Megrahi.

Mr MacAskill writes that he and the then First Minister tried to secure new powers for Holyrood in exchange for accepting a planned prisoner transfer agreement with Libya.

Mr Rennie said that the issue should be the first item of business on the new Cabinet Secretary for Justice’s desk.

Rennie said: “In both 2007 and 2009 the First Minister said he had no involvement in the Prisoner Transfer Agreement and had not been consulted.

“Now Kenny MacAskill is claiming that Scottish Ministers were actively involved, and were trading away their objections in return for more devolved powers.

“People will be concerned. Many were alarmed at the time that Tony Blair struck a deal in the desert with Colonel Gaddafi. Now it is suggested that Scottish ministers were involved at the highest level in attempts to trade off their personal concerns in return for new Scottish powers.

“The first item of business on the new Cabinet Secretary for Justice’s desk must be coming to Parliament to set the record straight.

“We need to know whether the discussions that Mr MacAskill refers to in his book took place, who else was involved in these talks and what SNP Ministers thought was a fair price for their silence.”