It seemed obvious that the prosecution's story of a man (Abdelbaset Ali Mohmed al Megrahi) using a fully adjustable and long-running digital timer and setting it so that, after two changes of aircraft, it still only cleared Heathrow by 38 minutes, was a little unlikely.

During the trial it seemed more likely to me that an air-pressure-sensitive improvised explosive device (IED) perfected by the PFLP-GC terrorist group centred in Damascus and allied to Iran, might have brought the plane down.

We heard the details of these devices in the Zeist courtroom from Crown witness Herr Gobel, a West German forensics expert, how these IEDs were available in the terrorist world in December 1988, and that they had a non-adjustable interval of 35-45 minutes from take-off to explosion if put on an airplane.

The Lockerbie aircraft managed just 38 minutes before the explosion. Herr Gobel's evidence made it plain that such a device could not have been flown from Frankfurt to Heathrow let alone from Malta, unless it was armed at Heathrow airport. Otherwise, it would have had to be introduced at Heathrow to avoid explosion en route. Yet there was no known evidence to support introduction or arming of such a device at Heathrow. We now know that there was precisely this evidence available but that the police/Crown Office had failed to pass it to the defence team or the court ("Vital evidence on Lockerbie was withheld", The Herald, May 3).

The point at issue is simple: why was this evidence not available to the trial court? The UN's special observer to the trial, Professor Hans Koechler, described the trial as not representing justice because of failures of the prosecution to share information with the defence.

Sooner or later the truth will out, but I fear that the longer it takes, the greater will be the damage to our legal system's reputation. The Scottish Criminal Cases Review Commission was correct in eventually deciding that "there may have been a miscarriage of justice". The appeal which followed, held in the knowledge of the plaintiff's progressive illness, seemed to some also to be subject to unwarranted delaying tactics by the Crown Office, though combined with the illness of a judge.

The Scottish Government does have the powers to order an inquiry. The relatives and the people of Scotland have a right to know the truth.

Dr Jim Swire,

Rowans Corner, Calf Lane, Chipping Campden, Gloucestershire.

YOUR revelations regarding the failure of the Crown Office to provide the defence with the material pertaining to the Heathrow break-in just hours before the Lockerbie bombing seriously undermines the integrity of the prosecution's case and, therefore, the integrity of the Scottish legal system.

The Crown Office dismissed the pre-trial significance of the break-in thus: "Even if this evidence had been heard by the trial court, it would not have reached a different verdict." This appears to derive from the wisdom of a Crown Office spokesman who said: "The Appeal Court was satisfied that, having heard direct evidence about the break-in at Heathrow, the verdict of the trial court was not a miscarriage of justice."

Arguably, that conclusion was influenced by the same kind of insular and complacent mindset that persuaded the Crown Office to withhold the Heathrow information from the defence.

The legal establishment in Scotland does not always react with optimum objectivity when confronted with challenges to its authority. When the Supreme Court overturned the unanimous decision of the High Court of Justiciary to dismiss Peter Cadder's appeal against his conviction (the appeal derived from human rights law regarding access to legal representation subsequent to arrest) the reaction of the legal establishment in Scotland was almost hysterical.

An informed bystander might be concerned that the Heathrow break-in should have been the subject of more robust and objective appraisal during Megrahi's first appeal.

Thomas Crooks,

81 Dundas Street, Edinburgh.

AFTER a particularly irritating passage through security at one of our international airports I recently felt the need to ask my MP for information regarding just how often these tiresome intrusions actually produced concrete results by uncovering terrorists or terrorist paraphernalia. I was politely informed that the Government does not disclose such information.

Why? Terrorists must know if and when they are being caught, why can't we be told? Could it be that we are all being made to jump through hoops just to deter others and they never find anything? How many octogenarian suicide bombers have there been and how many terrorists take their wife and children with them on the operation? Is it, like missile systems and fighter jets to protect the Olympic Games, all just to keep us on edge and afraid of retaliation from countries and parts of the world we seem happy to invade in search of oil?

David J Crawford,