Father hopes to learn the truth behind Lockerbie

The old Dutch bicycle layered with rust cost Jim Swire about £20, which he paid for in local currency. He has done it up a bit, given it a fresh coat of paint and hung from it a bright blue flag bearing the words, "Pan Am - the truth must be known".

For the next 12 months this bicycle will be Dr Swire's principal means of transport as he makes his way from a rented flat in the village of Zeist to oversee a matter that has all but taken over his life: Lockerbie.

The trial of the two Libyans accused of blowing up Pan Am flight 103 over the Scottish border town in December 1988 begins at Camp Zeist tomorrow. After more than 11 years, and given the twists and turns the case has taken, the fact that there is a trial seems to some nothing short of a miracle.

But those who expect the trial, on a former US base close to the Dutch city of Utrecht, will get to the bottom of the matter are in a minority. Dr Swire, whose daughter, Flora, was among the 270 victims, expects it to be no more than part of the investigative process, at best.

"I think it will show the guilt or innocence of the two accused," he said. "I don't know that at the moment. We have lived in a soup of conspiracy theories. We hope that the expert dissection of the evidence will show which parts of which theories are credible. I know no other way of separating the wheat from the chaff.

"Thirdly, this will finally take from the politicians the argument that we cannot have inquiries into air safety or intelligence matters."

Perhaps the only indisputable truth about flight 103 is that at 19.02 on 21 December 1988, the Boeing 747 exploded at 31,000ft above Lockerbie. All 259 passengers and crew were killed, as were 11 people from the town, previously known for a small collection of fossilised dinosaur footprints.

There have been countless theories about what happened and why: some say the explosion was the work of the Libyans, in revenge for Ronald Reagan's 1986 attack on Tripoli; others say it was the Iranians, avenging the accidental shooting down of one of its airliners by the USS Vincennes in July 1998; others say it was Palestinians trying to eliminate a CIA team preparing to rescue Western hostages from Beirut.

Lawyers for the defendants, Abdel Basset Ali al-Megrahi, 48, and al-Amin Khalifa Fhimah, 44, will say the bomb was planted by a convicted terrorist, Mohammed Abu Talb, a Palestinian born in Egypt who is now serving life for an attack on a Copenhagen synagogue.

Talb, a member of a Syrian-based group with links to Iran, was the original suspect. But in November 1991 US and British said they were indicting the two Libyans.

The prosecution's star witness is Abdu Maged Jiacha, who has been living under a witness protection scheme in the US. He will help the prosecution's argument that the two men, working for Libyan Arab Airlines in Malta, were actually Libyan intelligence officers.

What is accepted is that if the two Libyans, who deny murder, conspiracy to murder and contravention of an aviation security act, were responsible for the bombing, they were not acting alone.

But built into the trial are factors that may stand in the way of such inquiries. The deal that formed the basis on which the Libyan leader, Colonel Muammar al-Gaddafi, agreed to hand over the suspects in April 1999, included an assurance from the UN secretary general, Kofi Annan, that witnesses would not be asked about "any other operations or situations" involving Libya.

There is also the matter of how open the intelligence services of various countries are going to be when their operatives listed as witnesses are called to give evidence. In particular, there lies the matter of to what extent the US had advance warning of a possible attack on flight 103. Such matters are being played out in the incongruous setting of a sprawling 100-acre former military base, which has become Scottish territory for the length of the trial.

Officials spent £12m converting the camp into a prison, court and barracks for the armed Scottish police officers who guard it. The jail where the two men are held has walls 4ft thick, designed to withstand bombs and tanks. For the 200 police officers there are tennis courts, a football pitch, a gymnasium and recreation room with satellite television. It is the first time a Scottish court has convened on foreign soil and it is the first time a murder case has been held without a jury: three judges, with one reserve, will take the place of "12 good men and true" for the year the trial is expected to last.

Dr Swire and the other relatives of those who died that night in December 1998 are aware of the likely inadequacies of this trial. They would like to see further inquiries - for Dr Swire specifically into the current state of aviation safety - once this is completed.

Sticking by this trial is the best they can do. "What is the alternative?" Dr Swire asked last week. "I lost my daughter and it seemed to me that no one else gave a damn. I could not have just let my daughter go. I want to be able to look back and say I did everything I could.

"I had one eldest daughter and she is dead. I don't want her name pushed under the carpet of some bloody politician."