Four crucial pieces of evidence that secured the conviction of the man accused of the Lockerbie bombing were called into question yesterday as the long-awaited appeal of the Libyan Abdul Baset Ali al-Megrahi opened at the High Court in Edinburgh.

Setting out al-Megrahi's line of defence for the first time in public, his counsel, Margaret Scott, QC, challenged the prosecution's central claim - that the Libyan was linked to the Lockerbie atrocity because he had bought clothing that was found inside the suitcase that contained the bomb.

Ms Scott told the hearing that al-Megrahi, who has consistently protested his innocence, believed a “miscarriage of justice” had occurred at his original trial.

She said the defence team intended to challenge “four critical inferences” made during his original trial. These were that al-Megrahi bought the clothing that was in the suitcase containing the bomb; that the purchase happened on December 7, 1988; that the buyer knew the purpose for which the clothing was bought; and that the suitcase containing the bomb entered the system at Luqa airport, in Malta.

She said they were “not supported by the evidence” and that they were the products of “defective reasoning”. Ms Scott also described the case against her client as “wholly circumstantial” and said there was “insufficient evidence” to conclude he was guilty.

Al-Megrahi, 57, who is suffering from advanced prostate cancer, was not present at the Court of Criminal Appeal in Edinburgh, but watched the proceedings via a live link to Greenock Prison. Ms Scott said that his condition had deteriorated and that he would require frequent breaks for medical treatment.

The Lockerbie bombing on December 21, 1988, remains the worst ever terrorist act committed on British soil. All 259 men, women and children on board the aircraft died, along with 11 residents in the Scottish Borders town who were killed by falling wreckage. Initial inquiries suggested the involvement of a Syrian-based terrorist group, but suspicion later switched to Libya.

In January 2001, al-Megrahi, a former Libyan intelligence agent, was found guilty of the attack and sentenced to life imprisonment with a minimum term of at least 27 years. This is his second appeal.

Speaking at the opening of the proceedings yesterday, Ms Scott said: “The appellant's position is that there has been a miscarriage of justice.

“The trial court, on the basis of wholly circumstantial evidence, concluded beyond reasonable doubt that the appellant was involved in the commission of this crime. Our submission is it was wrong to do so.”

She went on to outline the four pieces of evidence she intends to challenge. “The appellant challenges the drawing of each of these critical inferences and consequently the conclusion that he was involved in the crime,” she said.

Ms Scott added: “No reasonable jury, properly directed, could have drawn the critical inferences which were necessary to return that verdict of guilty.” She also suggested other conclusions could have been drawn from the accepted evidence.

The new appeal is being headed by Scotland's senior judge, the Lord Justice General, Lord Hamilton, sitting with Lord Kingarth, Lord Eassie, Lord Wheatley and Lady Paton.

The appeal, which is expected to last about a year, will be heard in four-week sections, with a break of four weeks in between each set of hearings. The proceedings in Edinburgh could, however, be overtaken by other events. The UK Government is due to ratify a prisoner transfer agreement with Libya that would allow al-Megrahi to return home, but he would have to drop his appeal as part of the deal, leaving him condemned as a guilty man.

Among those in the packed courtroom yesterday were relatives of some of the victims of the Lockerbie disaster, including Dr Jim Swire, whose daughter Flora was killed, Kathleen and Jack Flynn, whose son John Patrick died, and the Rev John Mosey, who lost his daughter, Helga.

Mrs Flynn, 67, from New Jersey in the United States, said after the hearing that al-Megrahi should stay behind bars.

Speaking outside court, she said: “I think that he has committed a heinous crime. He was tried and convicted in a court of law under very serious circumstances and, I think, very fair and equitable circumstances.

“I'm sorry if Mr al-Megrahi has some illness problems, I don't wish that on anyone. But the point of the situation is that a heinous crime has been committed and justice has to be served.”

Dr Swire said: “I'm relieved that proceedings are continuing. So far, at least, we haven't seen a withdrawal of the appeal and for those who seek the truth that's got to be good news.

“The people who've got to resolve the issue are the Scottish courts.”

Mr Mosey said: “We hope to hear new evidence of how our daughter was murdered. We think that it will help us.”

The hearing continues.

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