Was Terry Waite freed as part of secret Lockerbie deal with Iran? Dr Swire's belief throws open again the dispute over the release on compassionate grounds of Abdelbaset al-Megrahi, the only person convicted of the worst terrorist atrocity in British history. Mr Waite, who was trying to negotiate the release of other hostages in 1987 when he was kidnapped, also believes - like Dr Swire - that Megrahi's conviction for mass murder is shrouded in doubt. Mr Waite said he could not be certain his release was linked to the blaming of Libya but said "it was an intriguing theory" that needed investigating. Megrahi's early release from a Scottish jail in 2009 - he was suffering from cancer and was sent back to Tripoli where he died last year - caused anger, especially among the families of American victims, who remain certain of Libya's involvement. The British relations of victims have been more sceptical of his involvement. Dr Swire is uncertain what to say in his three-minute "reflection" at the memorial service, but for several years he and other British families have led demands for a full inquiry, unconvinced by the police case that led to Megrahi's conviction in 2001. He plans to make passing reference to Mr Waite's release in his address, effectively linking it with the decision to pursue the case against Libya. "I don't like upsetting them [US relatives] but I am not prepared to accept something that is false for why my daughter was killed and why she wasn't protected," said Dr Swire. We have to have an inquiry and that burden [to air the truth] falls on my shoulders. I am supposed to have three minutes to talk. I don't wish to upset people who are coming to commemorate the people who died. It's a very difficult situation to call. I would love to make a statement saying the people of the two nations of Britain and the US have been deceived for reasons of politics but I am not going to do that. That would be too political for that venue. But I think I will be likely to say British relatives are not satisfied with the story. There will be Americans in the audience and that is one of the difficulties for me because what I am doing is extremely irritating for those who think they know what happened. Mr Waite, who returned to Beirut last year to meet his Hizbollah captors in a trip arranged with The Telegraph, is certainly not convinced by Megrahi's conviction. Mr Waite, who has campaigned for a new inquiry into Lockerbie, will attend the Westminster Abbey service. "There are many theories about why the Beirut hostages were released when they were," he said. One in particular is that responsibility for the Lockerbie bombing was transferred from Iran to Libya, and Iran, now absolved from responsibility for the atrocity, effected release of the final Western hostages including myself. This is an intriguing theory and takes its place alongside other speculations around this matter. Quite frankly, I cannot verify the theory and to this day have not the slightest idea why, at that particular time, I, along with Tom Sutherland, was released. The Beirut hostage affair and the Lockerbie bombing are fertile fields for conspiratorial theories. Many have been propounded and I wonder if the truth will ever emerge. I certainly do not know where it lies. On the anniversary of this dreadful event my thoughts are with all those who suffered and continue to suffer and my support is for those who relentlessly seek the truth. The 25th anniversary will inevitably bring back memories for those involved, as well as tensions between those who believe at least some form of justice has been delivered and those certain of a miscarriage and cover-up. The concerns over Megrahi's conviction essentially boil down to whether the bomb was placed in luggage in Malta or at Heathrow. Dr Swire, along with many others, believes that the bomb was placed on the plane at Heathrow and that it was linked to a break-in at the airport, the discovery of which was suppressed by the authorities. The bomb's timer is also subject to scrutiny, over who might have used or manufactured it. The plane, which was bound for New York, blew up 37 minutes after take off, killing all 243 passengers and 16 crew on board and 11 people on the ground. Clearly if Libya was not responsible, then who masterminded it remains a mystery. Syria and Iran have both been accused of involvement. In Iran's case, the motive is revenge for the shooting down of Iran Air Flight 655 in July 1988 by a missile fired from a US navy warship patrolling the Straits of Hormuz. Mohammed abu Talb, an Egyptian convicted in 1989 of the bombing of airline offices in Europe in the mid Eighties, is also a possible suspect too if Libya is discounted. It is alleged that he travelled to Malta two months before the Lockerbie bombing as part of the plot to bring down Pan Am Flight 103. Abu Talb has served his sentence for the other bombings and lives in Sweden, remaining silent on Lockerbie. The town has tried to move on from the events of 1988, and the theme of its service at Dryfesdale Church, home to the central memorial for the victims, will be "Looking Forward"; Megrahi's conviction led some civic leaders to suggest "Lockerbie has drawn a line under what has happened." The 11 victims on the ground died in Sherwood Crescent; the plane's wings and fuel tanks plummeted into the street with devastating effect. The explosion created a fireball that destroyed several houses and left behind a vast crater. There is a memorial garden where the houses once stood. Helen Fraser, now 65 and a former resident, has spoken for the first time of the tragedy, able to do so with the passing of time. Her testimony is aired in an ITV documentary to be broadcast on Tuesday evening. Last week she told The Telegraph of the flash of light, the explosion and her instinct to protect her two young children. In the days afterwards, having been temporarily evacuated from Sherwood Crescent, she returned to her home to be warned by a policeman that body parts were lying in her garden. "We had a Christmas rose blooming in the garden at the time and all I could do was to pick flowers from it and lay each one besides what resembled smouldering flesh and bones," she said. I couldn't not do something. It is such a strange thing when a policeman tells you there are bits of people in your garden. I just couldn't ignore it. Mrs Fraser, who was born in Lockerbie, moved away not long afterwards to Aberdeen, but still goes back frequently to see her family and friends. There aren't many people left in Sherwood Crescent now. People who live there suffer a bit from disaster fatigue," she said. She lived at one end of the street and the fireball hit the middle. At the other end, at number one, lived Father - now Canon - Patrick Keegans, 67, Lockerbie's Roman Catholic priest. He had been in the town only a year when the aircraft came down and remembers being at home about to visit two neighbours, Maurice and Dora Henry, for the evening. Mr and Mrs Henry both died in the crash. Their house took a direct hit. It was obliterated," said Canon Keegans, who is now administrator at St Margaret's Cathedral in Ayr and will return to Lockerbie for the memorial services. He backs Dr Swire's call for a new inquiry. I am very certain Megrahi had nothing to do with this. Lockerbie coped very, very well at the time. They were not interested in the politics of it all. They just wanted to go back to how life was before. But I don't think you can look forward if you haven't dealt with the past. This is unresolved business and it is very difficult to get on with your lives when such unresolved issues are out there. On a personal level, it is difficult [to return] given I have been such a strong supporter of Megrahi and very much convinced justice has been denied. My support for Megrahi does not go down well with the Americans. Two years ago Gaddafi was murdered by a rebel mob, which had overthrown his regime. But since then no further documentation has emerged from Libya providing evidence of its involvement. Dr Swire says there is further proof that Libya was blamed needlessly, accepting responsibility for the attack that led to Megrahi being handed over. In return, Libya was able to come out of the cold and begin trading with the West, opening up its oil and gas fields. A quarter of a century on, the questions over Lockerbie, for Dr Swire and many others, remain unanswered. Saturday's services may open more of those wounds that time should have healed.