US film-maker Allan Francovich, whose controversial documentary challenged the official British and American view that the Lockerbie bombing was solely the work of two Libyan agents, has died.

A friend said Mr Francovich collapsed on April 17 at Houston airport, Texas. He was pronounced dead at hospital where the cause was given as a heart attack.

Mr David Ben-Aryeah, a friend, said Mr Francovich would be cremated in San Antonio, and that his ashes would later be brought to Skye for a ''service of celebration''.

Mr Francovich, who was in his early 50s, had written a script while on Skye and had also visited the island with bereaved Lockerbie parent, Dr Jim Swire, while making the Lockerbie documentary ''The Maltese Double Cross.''

Mr Ben-Aryeah said: ''While he was there he came to love the island, its tranquillity, its scenery and its people.''

The American made several other controversial documentaries, mostly concerning the work of the Central Intelligence Agency.

The Maltese Double Cross, which was shown to MPs in the Commons before being screened publicly in 1995, challenged the official US and British version of how a bomb brought down the New York-bound Pan Am Flight 103 over Lockerbie on December 21, 1988.

Last night Linlithgow Labour MP Tam Dalyell, who collaborated with Mr Francovich in making the documentary, said he was ''very upset'' by news of his death.

The MP described him as ''one of the most persistent seekers-of-truth'' he had ever met, ''an exceedingly brave man''.

Dr Swire, whose daughter died in the disaster, said he would be ''very much missed'' by those who considered that the truth on the Lockerbie disaster had yet to be told.

The 90-minute documentary, directed by Mr Francovich, claimed a huge cover-up had taken place. The film maintained that Iran and Syria plotted to bring down the aircraft as revenge for the US shooting down an Iranian Airbus months before the Lockerbie tragedy.

It argued that the authorities knew the plane was going to be bombed, but did nothing to prevent it for fear of exposing a US-sponsored drug-smuggling operation.

Scotland's top law officer at the time, the Lord Advocate, Lord Rodger of Earlsferry, criticised the screening by Channel 4. He said he deprecated all attempts to give a version of the atrocity ''from whatever angle'' while criminal proceedings were pending.

However, relatives of the 270 people who died welcomed the showing of the documentary saying people should be allowed ''to make up their own minds''.

Mr Dalyell said: ''It was my privilege to be Allan Francovich's collaborator in making the film, The Maltese Double Cross, which I believe exposed the truth that the Libyans were not responsible for the Lockerbie crime.

''I could not criticise the American and British governments more strongly for their refusal to address properly the explanations of Lockerbie.''

Dr Swire said: ''Speaking personally we view the loss of Allan as the loss of a close friend whose humour and determination was much appreciated and will be greatly missed.

Obituary - Page 22