A minister has told the man who faces dying in jail for the Lockerbie tragedy that he will forgive him for killing his daughter in Britain's worst terrorist atrocity.

On the 20th anniversary of the tragedy, Rev John Mosey revealed that he was convinced the authorities had convicted the wrong man for bombing Pan Am Flight 103.

His talented musician daughter Helga, 19, was among the 259 who died when the plane exploded and wiped out a street in the Scottish village.

But after hearing all the evidence, the Herefordshire churchman does not believe the 56-year-old Libyan agent, jailed for the bombing in 2001, planted the bomb and has visited Abdel Basset Ali al-Megrahi behind bars.

He said: " I have spoken to the gentleman in prison, Mr Megrahi, and said to him although I seriously doubt – 85 per cent doubt – his guilt, if I am wrong he needs to know that as far as our family is concerned he is forgiven."

Mr Mosey was speaking hours before leading a memorial service at Heathrow Airport for friends and relatives to remember loved ones on the anniversary.

At 7.03pm exactly, he led a minute's silence to mark the moment the plane came down onto the village of Lockerbie.

Most of those who died were Americans on their way home for Christmas and there were events on both sides of the Atlantic to remember those who died in the plane crash that shocked the world.

In Lockerbie, where 11 people died on the ground, there were poignant remembrance services to mark the anniversary.

Rev Mosey led a low-key service for about 300 relatives and friends at a Heathrow Airport where the names of the 33 British victims were read out. Thousands of people joined in a minute's silence last night to remember the 270 victims of the bombing.

Tributes were paid at services across the UK and US on the anniversary of the atrocity, when Pan Am Flight 103 from Heathrow to New York exploded in the skies above the Scottish town in 1988.

All 259 people on board were killed and a further 11 died in Lockerbie where the wreckage fell to the ground.

Their names were read out at vigils arranged to coincide with the moment of the disaster, minutes after 7pm.

In Lockerbie, hundreds of residents gathered at ceremonies at Dryfesdale and Tundergarth churches.

The Rev Sandy Stoddart told the congregation at Dryfesdale: "I have printed 270 names on the back of the order of service. This is a list of those who died. But it is not a list of the victims, because we can never list all those names. Nobody but God knows all the names on the list."

Since losing his daughter Rev Mosey has been using his compensation from the Libyans to help children in the developing world and marked the 15th anniversary of his daughter's death by opening an Indian orphanage in her memory. He said recently: "In the first five to 10 years after her death I thought about her every single day, every hour. Twenty years on, time heals to some degree, but I still think about her very often."

He has also spent years travelling the world fighting for the truth and sat through all but one week of al-Megrahi's nine-month trial before deciding the Libyan, who is dying of prostate cancer, was probably not responsible.

British relatives' spokesman, Dr Jim Swire, who also lost a daughter, also believes they might have the wrong man and many families still want a public inquiry into events leading up to the bombing.

Lawyers have failed to free the cancer stricken Libyan on humanitarian grounds and are pinning their bids on appeal in January. He may not live that long.

But yesterday relatives forgot their quest to find out who killed so many on 21 December 1988, to simply remember those who died.