Lawyers acting for the Lockerbie bomber are expected to ask the High Court to examine claims that vital documents were kept from the trial defence team.
Megrahi is making a second appeal against his conviction
It is believed the documents may have undermined the case against Abdelbaset Ali Mohmed al-Megrahi.
Megrahi is currently serving a minimum of 27 years for the 1988 atrocity in which 270 people died when Pan-Am flight 103 exploded over Lockerbie.
He is awaiting an appeal on the grounds of a possible miscarriage of justice.
It is understood the Scottish Criminal Cases Review Commission which looked at Megrahi's conviction in 2001 discovered documents that were seen by the prosecution but not by the defence.
The documents, which relate to the timer which allegedly detonated the Lockerbie bomb, are believed to have come from the American CIA - which demanded that they were not disclosed.
The review commission has used this as one of the grounds for referring Megrahi's case to appeal judges.
BBC Scotland home affairs correspondent Reevel Alderson said it was not known exactly what the documents contain.
Megrahi's lawyer has also declined to confirm that they cast doubt on the evidence put before the original trial about the timer fragments found in Megrahi's clothes.
It is likely a procedural hearing will take place in Edinburgh later this year but the full appeal will not be heard until next year.