The identification of the man convicted of the 1988 Lockerbie bombing was "highly prejudicial" as a key witness saw a photograph linking him to the crime shortly before the trial, a Scottish appeals court was told on Wednesday.
The bombing of Pan Am Flight 103 over the Scottish town of Lockerbie on December 21, 1988, killed 270 people in Britain's largest terrorist atrocity.
Former Libyan intelligence officer Abdelbaset Mohmet Al-Megrahi, who died in 2012, was convicted of mass murder by three judges at a special Scottish court sitting in the Netherlands in 2001 and was jailed for life.
His family's lawyer said shopkeeper Tony Gauci's original testimony that Megrahi bought clothing in his shop in Malta that was later found in a suitcase containing the bomb, was "virtually of no value".
"The circumstances in which that dock identification was made was highly prejudicial," Claire Mitchell told five judges at the High Court of Justiciary in Edinburgh.
"The identification was made shortly after he (Gauci) had seen a photograph which he had of course seen before, of an article suggesting that Mr Megrahi may have been the bomber...
"I think the wording of it is 'who planted the Lockerbie bomb?' and underneath there is a photograph of the appellant (Megrahi)."
Identification of a defendant in such a manner was "something no court could have placed any weight on", she added.
Documents battle
Megrahi was released from prison on health grounds in 2009 and died in Tripoli three years later aged 60.
His family won an appeal to Scotland's highest criminal court after an independent case review body said earlier this year that a miscarriage of justice may have occurred.
Central to the original prosecution case was that Megrahi was responsible for buying the brown Samsonite suitcase used to plant the bomb in the ill-fated Boeing 747's cargo hold.
But Mitchell maintains they had not proved that Megrahi was the person who bought the clothing found in the suitcase at a shop in Malta on December 7, 1988.
The Scottish Criminal Cases Review Commission (SCCRC) in March referred the case to the High Court of Justiciary on the grounds that an "unreasonable verdict" was returned.
It also highlighted "non-disclosure" of evidence to Megrahi's defence team.
The High Court has upheld a secrecy order signed in August by UK foreign secretary Dominic Raab to withhold intelligence documents related to the case on grounds of national security.
In 2008, then-foreign secretary David Miliband also refused to release the papers before Megrahi's second appeal.
The Megrahi family lawyers believe the documents are central to their appeal.
Megrahi's first appeal was dismissed in 2002 and a second abandoned after he was diagnosed with terminal cancer.
The judges, including Scotland's most senior jurist, Lord Justice General Colin Sutherland, are hearing the current case, which is due to last until Friday.
The Megrahi family's legal team are taking part remotely from Glasgow. A ruling is expected at a later date.