A Scottish legal body has decided it is "not in the interests of justice" for it to continue to review the conviction of Abdelbaset al-Megrahi over the Lockerbie bombing.

The Libyan, who died protesting his innocence in 2012, was found guilty of the 1988 bombing of Pan Am flight 103 over Scotland on December 21 in which 270 people were killed.

Campaigners, said to be supported by Megrahi's family, last year launched an application with the Scottish Criminal Cases Review Commission (SCCRC) seeking a further review of his conviction in a bid to clear his name.

They argued his case is the "worst miscarriage of justice in British legal history" and hoped it would be referred back to the High Court for a fresh appeal.

But the SCCRC today announced it has refused the application.

The SCCRC is the Scottish body which reviews alleged miscarriages of justice in criminal cases and has the power to refer a case back before senior judges.

A decision published by the body expressed frustration over its lack of access to certain paperwork, including defence appeal papers from Megrahi's former solicitors.

It said it had decided to end the current review "with some regret".

Megrahi was jailed for life and lost his first appeal against the mass murder conviction in 2002.

An earlier investigation by the SCCRC led to a finding in 2007 of six grounds where it believed a miscarriage of justice may have occurred, paving the way for a second appeal.

But Megrahi dropped that appeal in 2009 before being released from jail by the Scottish Government on compassionate grounds in light of his terminal cancer.

Last year's fresh approach to the SCCRC - said to involve 24 British relatives of those who died in the atrocity and six immediate members of Megrahi's family - was believed to be the first time in UK legal history that relatives of murdered victims had united with the relatives of a convicted deceased in such a way.

Dr Jim Swire, whose 23-year-old daughter Flora died in the bombing, was among those involved in the Justice for Megrahi group at the heart of the campaign.

High Court judges ruled earlier this year that relatives of the victims of the Lockerbie bombing should not be allowed to pursue an appeal on behalf of the only man convicted of the atrocity.

Refusing the application, the commission said it has "little confidence" in the willingness of the Megrahi family to co-operate with the review or to take forward any subsequent appeal.

Setting out the commission's decision, SCCRC chairman Jean Couper said: "A great deal of public money and time was expended on the commission's original review of Mr Megrahi's case which resulted, in 2007, in him being given the opportunity to challenge his conviction before the High Court by way of a second appeal.

"In 2009, along with his legal team, Mr Megrahi decided to abandon that appeal. Before agreeing to spend further public money on a fresh review the commission required to consider the reasons why he chose to do so.

"It is extremely frustrating that the relevant papers, which the commission believes are currently with the late Mr Megrahi's solicitors, Messrs Taylor and Kelly, and with the Megrahi family, have not been forthcoming despite repeated requests from the commission. Therefore, and with some regret, we have decided to end the current review."

She added: "It remains open in the future for the matter to be considered again by the commission, but it is unlikely that any future application will be accepted for review unless it is accompanied with the appropriate defence papers.

"This will require the co-operation of the late Mr Megrahi's solicitors and his family."

Aamer Anwar, solicitor for the family of Megrahi and some of the victims' relatives, said: "Those who instruct us are deeply disappointed with the Commission's decision.

"However it is hoped that once the security situation improves in Libya that we will be able to pursue the SCCRC application in the hope that the Megrahi case is successfully referred back to the Court of Appeal."

A spokesman for Taylor and Kelly said it "cannot deliver up papers in our possession simply upon request".

"It is with some surprise that we learn today that the commission have come to the view that papers have not been forthcoming from us as Mr Megrahi's appeal representatives," the spokesman said.

"As soon as a request was made from the commission we asked to be advised of the basis of the request - the power of the commission to ask for access to material. Despite making clear that we were anxious to assist, we have not as yet been told of the commission's authority to have access to amongst other things private communications. As solicitors we cannot deliver up papers in our possession simply upon request, even to a body such as the commission.

"No indication was given to us until today that the commission were interested in the part of our actings relating to Mr Megrahi's appeal being abandoned. The commission have very wide powers indeed. They could have made application to the court for access to materials. In any such application, they would clearly have been required to state the basis of the request, and the basis for any court to order us as solicitors to have to part with confidential papers.

"We prefaced that in communications with them and asked them to provide authority for any application. We remain in the dark on this important point."

The spokesman added: "The basis of our searching for a proper basis of the commission's request was not nit picking but, rather to ensure that our clients remain confident that the privileged communication between solicitor and client will not be easily violated.

"It is a pity that the commission have decided upon this application on such a basis. We are sorry that the commission has not given further thought to formulating a basis for their request and sharing with us what was being sought."