A key witness whose evidence helped to secure the conviction of Abdelbaset al-Megrahi over the Lockerbie bombing has died, it is understood.
Maltese shopkeeper Tony Gauci died of natural causes at his home at the age of 75, the Times of Malta reported.
It is understood the authorities in Scotland have been made aware of the death.
Mr Gauci ran a clothes shop in Swieqi, Malta, at the time of the bombing of Pan Am flight 103 and claimed that Megrahi bought a piece of clothing found among the debris of the aircraft.
His evidence helped to secure the 2001 conviction of the former Libyan intelligence officer for the atrocity in which 270 people died, including 11 people on the ground.
But some doubts were subsequently raised about Mr Gauci's reliability.
Megrahi was the only person to have been convicted of the bombing over the south of Scotland on December 21 1988.
He was jailed for life but an investigation by the Scottish Criminal Cases Review Commission (SCCRC) led to a finding in 2007 of six grounds where it is believed a miscarriage of justice may have occurred, paving the way for a second appeal.
The Libyan dropped that appeal in 2009 before being released from jail on compassionate grounds due to his terminal prostate cancer. He died protesting his innocence in Libya in 2012.
The trial judgment detailed how the three judges were satisfied Megrahi had walked into Mr Gauci's shop and bought items of clothing which ended up packed around the bomb that exploded in a suitcase on board the flight.
But the SCCRC said doubt had been cast on some of the evidence which helped convict Megrahi, in particular evidence relating to the visit to Mr Gauci's shop.
New evidence suggested the clothing had been bought at a time when there was no evidence that Megrahi was in Malta, said the SCCRC.
And other evidence not available at the trial undermined Mr Gauci's identification of him, it said.
In his last interview, Megrahi insisted he had ''never seen'' Mr Gauci and had not bought clothes from him.
In 2014 Scotland's then Lord Advocate, Frank Mulholland, reaffirmed his belief in Megrahi's guilt.
The following year, Scottish prosecutors revealed they have identified two Libyans as suspects over the atrocity.