The Scottish Criminal Cases Review Commission dropped its investigation into Megrahi on Thursday, expressing frustration at its failure to obtain legal papers relating to a 2009 appeal.
The SCCRC had been examining the conviction of Megrahi following an application by relatives of victims of the 1988 atrocity.
But it said it had decided to refuse the application, expressing its frustration at its inability to obtain defence papers from Megrahi’s own appeal, which he abandoned in 2009 after he was released from prison on compassionate grounds.
The SCCRC also said it had “little confidence” in the willingness of the Megrahi family to co-operate with the review or to take forward any subsequent appeal.
But John Ashton, whose book Megrahi: You Are My Jury was published in 2012, criticised the SCCRC for failing to contact him about the case.
Speaking to the BBC, Mr Ashton said the SCCRC could have obtained defence papers relating to Megrahi’s 2009 appeal from him.
He said: “They could easily do that by asking me for the papers. I have them because Mr Megrahi gave them to me.”
Asked about the SCCRC decision, he said: “It’s hasty and incompetent. They could have got these papers quite easily by approaching me. If they wanted to get to the bottom of why Mr Megrahi abandoned his previous appeal they could have interviewed his previous solicitor, Tony Kelly. They could have interviewed me. They have an affidavit from me, they have paper work which indicates I interviewed Mr Megrahi and got his side of the story. I’m a witness in this case and they haven’t bothered to interview me.”
The SCCRC decided on Thursday that is was “not in the interests of justice” to further review Megrahi’s conviction.
It declined to respond to Mr Ashton comments.