by Severin Carrell, Scotland correspondent
The key prosecution witness in the Lockerbie bombing trial was allegedly offered a $2m reward in return for giving evidence, raising fresh doubts about the safety of the case.
Lawyers for Abdelbaset Ali Mohmed al-Megrahi, the Libyan convicted of murdering 270 people on board Pan Am Flight 103, have evidence that detectives investigating the bombing recommended that Tony Gauci, a shopkeeper from Malta, be given the payment after the case ended.
Mr Gauci's testimony at the trial was crucial to al-Megrahi's conviction. He told the trial at Camp Zeist in the Netherlands that the Libyan had bought clothes at his shop which the prosecution claimed were packed into the suitcase bomb that exploded over Lockerbie on December 21 1988.
The defence team believe Mr Gauci may have received a larger sum from the US authorities. His role in the case is to be central to al-Megrahi's appeal against his conviction, which the Scottish Criminal Cases Review Commission said was unsafe.
They are to press for full disclosure of these payments, and the release of a potentially vital US document which is thought to cast doubt on official accounts about the timer allegedly used in the bombing, at an appeal hearing next week.
The secret document is believed to dispute prosecution claims that al-Megrahi used a digital timer bought from a Swiss company, Mebo, and then planted the bomb on a flight from Malta to Germany - a disclosure which would fatally undermine his conviction.