Ahmed Jibril who has been on America's 'most wanted' list for decades was reported to have been assassinated by an al-Qaeda affiliated group.
Jordanian media reported that Jabhat al-Nusra, an off-shoot of al-Qaeda, used an improvised explosive device to kill the 76-year-old who is a strong supporter of Syria's President Assad.
The reports state that the attack on Jibril took place several days ago and although the Palestinian leader survived the initial attack he succumbed to his injuries in a Damascus hospital on Monday.
Yesterday the Liberation of Palestine General Command (PFLP-GC), which Jibril founded and remains general secretary, denied that he was dead or even wounded.
Robert Black, Professor Emeritus of Scottish Law at the University of Edinburgh, often referred to as the architect of the Lockerbie trial at Camp Zeist in the Netherlands did not believe that if Jibril died that it would make much difference to the search for the truth about the disaster.
He said: "He was never likely himself to admit responsibility.
"It is possible, though unlikely, that his absence from the scene might give others the courage to speak up about his involvement.
"But I think we will just be left with what evidence already exists, particularly the $10million payment from Iran into the PFLP-GC's coffers a few days after 21 December 1988.
"There are those in the West and in the Middle East who think that Jibril and the PFLP-GC were never really important figures in the Palestinian struggle: good at raking in funds but leaving the fighting to others.
"Certainly, Jibril and the PFLP-GC are thought by some to be seriously in the frame, as contractors for Iran which was seeking revenge for the shooting down of Iran Air flight 655 by the USS Vincennes in July 1988, six months before Lockerbie.
He added: "And at the Camp Zeist trial the defence lodged a special defence of incrimination blaming Jibril and the PFLP-GC for the crime."
In March an Iranian defector, a former intelligence agent, claimed that the Lockerbie attack was ordered by Iran in revenge for the accidental downing of an Iranian commercial jet by the US Navy in 1988.
It was carried out by Palestinian terrorists based in Syria, he said, and not on the orders of Libyan dictator Muammar Gaddafi. The atrocity killed 243 passengers, 16 crew and a further 11 people on the ground in Lockerbie.
Ex-spy Abolghassem Mesbahi claimed in a documentary that former Iranian leader Ayatollah Khomeini wanted to mirror the 1988 US strike on an Iranian Airbus and recruited a Syrian-based group to plan an attack.
Evidence unearthed by the documentary-makers included the names of four suspects belonging to the Syrian-based radical group, the PFLP-GC, with Ahmed Jibril identified as the plot's mastermind.
It was claimed he recruited one of his most trusted deputies Hafez Dalkamoni, a Palestinian PFLP-GC member, and Jordanian bomb-maker Marwan Khreesat
These recruits were arrested by German police, who discovered four bombs, months before Lockerbie. A US intelligence cable obtained by Megrahi's defence team is alleged to have said: "The execution of the operation was contracted to Ahmed Jibril…money was given to Jibril upfront in Damascus for initial expenses - the mission was to blow up a Pan Am flight."
PFLP-GC's name was identified during the Lockerbie trial - in which Libyan agent Abdelbaset al-Megrahi was convicted of the bombing of Pan Am flight 103 in 1989. Megrahi, who was released from jail by the Scottish Government on compassionate grounds after being diagnosed with prostate cancer, died in 2012 protesting his innocence and his family said they planned to appeal against his conviction.