REVELATIONS in The Herald the UK Government tried to suppress have fuelled calls for a public inquiry into the Lockerbie bombing.

Yesterday, we revealed a document the UK Government has blocked for more than 20 years, which has never been aired in public or shared with the courts, originally came from Jordan and indicates a Palestinian terrorist group was involved in the bombing that killed 270 people – which the UK Government has vehemently denied.

The UK Government went to considerable lengths to prevent details of the document – which casts further doubt on the safety of the conviction of Abdelbaset Ali Mohmed al Megrahi – being published by The Herald.

Dr Jim Swire, whose daughter Flora died in the atrocity, said: "No-one has been braver than The Herald in searching for the truth about Lockerbie. For this news to break now goes to the core of features of this case which have worried me for a long time. One is the professed ignorance of the UK Prime Minister and Scottish First Minister when they say they uphold the verdict of the trial and [will] not hold an inquiry.

"During the second appeal in Edinburgh, when the Advocate General spoke he said a Public Interest Immunity [PII] certificate had been granted by the then Foreign Secretary David Miliband. I knew then the establishment of the countries in which I live were opposing my right to know who really murdered my daughter and all those other people, and to know why their precious lives were not protected."

The document incriminates the Popular Front for the Liberation of Palestine – General Command (PFLP-GC) in the bombing. The PFLP-GC were the original suspects in the investigation into the atrocity. However, by 1991 police and prosecutors were entirely focused on Libya.

The UK Government arranged for the document to be covered by Public Interest Immunity on national security grounds.

Willie Rennie MSP, leader of the Scottish Liberal Democrats, said: "This adds further weight to calls for a Scottish public inquiry into the Lockerbie prosecution. Accusations of suppressing evidence and withholding important documents from those at the heart of the investigation cannot be swept under the carpet. The First Minister should order a Scottish public inquiry to ensure the integrity and fairness of the Scottish justice system is put beyond doubt."

It is thought the document could fatally undermine the case against Megrahi, who died of cancer last month. Tony Kelly, Megrahi's solicitor, said the fact the Appeal Court, defence team and Megrahi were never allowed access to it is a "tragedy".

"The publication of details of the document in yesterday's Herald – previously subject to a PII certificate signed by the Foreign Secretary in the course of the appeal proceedings – was the first inkling I had about the content and source of the document," he said. "What a great pity."

John Ashton, the author of Megrahi: You Are My Jury, said yesterday: "Mr Megrahi spent 10 years in prison and went to his grave still bearing the weight of his conviction. If this, and all the other important evidence that we now know of, had been disclosed to his lawyers, he should have walked from court a free man and would have spent the last decade with his family. By resisting a public inquiry into the case, the Scottish Government is fuelling the biggest scandal of the country's post-devolution era."

Patrick Harvie MSP, Scottish Green Party co-convener, said: "The Herald's latest twist adds to the long-held doubts about Mr Megrahi's conviction. In its apparent attempt to prevent The Herald talking about this document, the Foreign Office refers to the UK's international relations being harmed. Surely the real risk is to our reputation for justice. A public inquiry would help address this sorry saga."

A Scottish Government spokesman said: "It is the case that the Crown Office wanted to provide this information to Mr Megrahi's legal team during the second appeal and made this clear to the court, but it could not be done because of the UK Government's Public Interest Immunity certificate.

"The issues being raised in relation to the conviction itself must be a matter for a court of law – Mr Megrahi was convicted in a court of law, his conviction was upheld on appeal, and that is the only appropriate place for his guilt or innocence to be determined. It remains open for relatives of Mr Megrahi or the relatives of the victims of the Lockerbie atrocity to ask the SCCRC (Scottish Criminal Cases Review Commission) to refer the case to the Appeal Court again on a posthumous basis."