FRESH doubt has been cast over the conviction of the Lockerbie bomber after it emerged a document containing vital evidence about the bomb timer has never been shown to the defence.
The Scotsman has learned that the failure to disclose the classified document, which concerns the supply of timers identical to the one said to have been used to blow up Pan Am Flight 103, led a review body that examined the case against Abdelbaset Ali Mohmed al-Megrahi to conclude a miscarriage of justice may have occurred.
It was not previously known that doubts over the timer were grounds for an appeal.
The content of the document remains a mystery as sensitive details of the report seen by the Scottish Criminal Cases Review Commission (SCCRC) have been blacked out, or redacted. It is understood that security services also prevented the SCCRC from releasing the report, or disclosing any of its contents, to Megrahi or his lawyers, who are thought likely to seek a court order forcing the Crown Office to hand it over.
The document is among six points in the case which the SCCRC has concluded casts doubt over the reliability of Megrahi's conviction. The SCCRC detailed some of these in a summary of its findings in June, but others, including the failure to disclose this document, remained secret.
However, disclosure, or the lack of it, has already been exposed as one of the concerns of the SCCRC, which has ruled a fresh appeal must be heard.
Among the grounds for a potential miscarriage of justice was the discovery of new evidence, not made available to the defence, that casts doubt over the reliability of the identification by Maltese shopkeeper Tony Gauci of Megrahi as the man who bought clothes found wrapped around the bomb used to blow up the plane, murdering 259 passengers and crew on board the plane, and 11 town residents.
The evidence showed that four days before Mr Gauci picked the Libyan out in an identity parade, the witness saw a photograph of him in a magazine linking him to the bombing.
The Lockerbie trial is one of several cases in which the prosecution has been shown to have withheld potentially vital evidence from the defence.
Last July, Stuart Gair was cleared after spending 17 years protesting his innocence over a murder involving a knife.
His conviction was quashed after Lord Abernethy singled out a failure to disclose witness statements to his lawyers deprived the defence of a "powerful argument" on identification.
In December, four brothers accused of murder were freed by the High Court in Glasgow after the Crown failed to provide more than 100 witness statements to the defence.
The hidden evidence in the Lockerbie case relates to the timer said to have detonated the bomb. It was identified by a fragment of circuit board said to have been found in the remains of a shirt among the debris.
The timers were said to have been supplied only to Libya. But then it was shown at least two had also been supplied to the East German Stasi.
Last night neither the SCCRC or Megrahi's lawyer, Tony Kelly, were prepared to comment.
Tam Dalyell, the former MP who believes Megrahi is innocent, said: "At issue now is whether there should be a challenge to the Crown Office."
POINTS FOR APPEAL
SIX years on from the landmark trial, the matter of who was responsible for the Lockerbie bombing remains unresolved.
The Scottish Criminal Cases Review Commission identified six aspects of the case against Abdelbaset Ali Mohmed al-Megrahi where it believes that "a miscarriage of justice may have occurred". One of those related to the day that clothes believed to have been wrapped around the bomb were bought from a shop in Malta.
The court had accepted the Crown's position that the clothes were bought on 7 December, 1988, when there was evidence that Megrahi had been on the island. But the commission found there was "no reasonable basis" for the judges to reach this conclusion.
It also said that new evidence, not heard at the trial, together with the testimony of the shopkeeper, Tony Gauci, indicated the items were bought before 6 December, when Megrahi was not on the island.