Abdelbaset Ali Mohmed al-Megrahi was the former member of the Libyan secret services who was found guilty of the Lockerbie bombing and sentenced to life in prison.

On December 21 1988, Pan Am flight 103, a Boeing 747 named Clipper Maid of the Seas, exploded above the town of Lockerbie with the loss of 270 lives - 243 passengers, 16 crew and 16 on the ground.

A lengthy investigation into the cause of the explosion established that it had been a bomb that had destroyed the aircraft. Tests established where the bomb had been placed, and fragments of a suitcase believed to have contained it were among the 10,000 piece of debris recovered from the crash site. Also recovered were fragments of a cassette player - the same type that had been used for a bomb seized in Germany by police and baby clothes that were thought to have been in the same suitcase.

A fragment of a timer device was linked to Libya, and the unaccompanied case that had contained the device was found to have entered the airline's baggage system at Malta's Luqa airport. A shopkeeper in Malta testified that he had sold the baby clothes to a Libyan he identified as Megrahi.

In May 2000, Megrahi and co-accused Al-Amin Khalifah Fhimah stood trial in the Netherlands, at a Scottish court convening at Camp Zeist, a former military base. Megrahi was convicted by a panel of three judges in January 2001 and sentenced to life in prison, Fhimah was found not guilty.

Megrahi was initially held in Glasgow's Barlinnie Prison, and later transferred to Greenock Prison.

An appeal against Megrahi's conviction was rejected in 2002, and Megrahi was granted leave to appeal against his conviction for a second time in 2007. This followed a four-year review by the Scottish Criminal Cases Review Committee (SCCRC), who concluded that a miscarriage of justice could have occurred.

Information that cast doubts over the conviction included claims that documents relating to the device that detonated the bomb were withheld form the defence team, that the Maltese shopkeeper was allegedly paid for testifying against Megrahi, that a witness was allegedly offered money by the FBU to identify the fragment of the detonator and link it to Libya and that a timer had been stolen from its manufacturer and given to an official investigator.

In 2008, five judges rejected a submission by the Crown that the scope of this second appeal should be limited to the specific grounds of appeal that were identified by the SCCRC.

In September 2008, he was taken under armed escort to Greenock’s Inverclyde Hospital for medical treatment, and it was confirmed one month later that he was suffering from advanced prostate cancer.

It emerged in summer 2009 that no decision on the appeal will be reached until the autumn, after one of the judges involved underwent heart surgery.

A treaty between Britain and Libya allows for the transfer of prisoners, but no decision can be made by the Scottish Government if there are unfinished legal proceedings.

At a hearing at the High Court in Edinburgh in August 2009, the judge heard from Megrahi's legal team that they wanted to withdraw the second appeal, and that Megrahi's health had declined, his prognosis being described as "extremely limited."