British director Michael Winterbottom tackles the moral cost of the US-led war on terrorism in "The Road to Guantanamo", which emerged Tuesday as a frontrunner at the 56th Berlin Film Festival. The film blends documentary-style interviews with scenes played by actors to tell the true story of three British Muslims who were held for two years at the detention center for terror suspects at the US naval base in Cuba without charge or legal representation.

The young men of Pakistani and Bengali origin - known in the press as the Tipton Three after their hometown in central England - were picked up in Afghanistan in late 2001 and mistaken for Taliban fighters. They were whisked to Guantanamo in January 2002 and finally released in March 2004 under pressure from the British government.

Now in their twenties, all three have maintained their innocence, insisting they were in Pakistan to attend a wedding and hoped to do humanitarian work in Afghanistan. "The point of making it is to remind people about how bizarre it is that somewhere like Guantanamo exists," said Winterbottom, 44, who was joined at a post-screening news conference by two of the former prisoners.

"If someone had said five years ago that the American government was going to create a place, in Cuba of all places, because holding those people would be illegal in their country so they couldn't take them to their country... they would hold people for four years without any trial and often even without charge, people would have thought you were crazy."

Former inmate Shafiq Rasul said he had agreed to cooperate with Winterbottom because his name had still not been formally cleared. "Nobody's ever said we were innocent," he said in a broad Birmingham accent. "We were released because a deal was made with the British government." Rasul said he was pleased a wide audience was now going to get a glimpse of what the 500 people still held at Guantanamo experience.

"Everything that happened, you wanted to be in the film," he said. "It's very emotional being there - seeing other people, other detainees, things that they were going through. We had it rough but we didn't have it as bad as others, for example the Arabs. Because we could speak English and communicate with people."

The film shows gruelling scenes of beatings by interrogators, prisoners being held for hours in "stress positions", rock music being blasted into solitary confinement cells and desecration of the Koran. A second former prisoner, Ruhel Ahmed, said he was still haunted by nightmares of his ordeal. "In the beginning it was hard when we were released. It was hard to sleep," he said. "You'd wake up sweating and then you'd realize you were back home."

Winterbottom, who clinched the Berlin Film Festival's Golden Bear top prize in 2003 for his refugee drama "In This World", said the picture was going to be shown on British television next month and that he was hoping for international cinema distribution. The screening, which received a lengthy round of applause, was aptly timed as a draft of a United Nations report on Guantanamo emerged, finding that the US treatment of detainees violates their rights to physical and mental health and, in some cases, constitutes torture.

According to a copy leaked to the Los Angeles Times, the text also urges Washington to close the prison and try the detainees on US territory, charging that the continued detention is a distortion of international law. Festival director Dieter Kosslick said before the event began February 9 that he had handpicked "The Road to Guantanamo" in protest against the prison and said he would like to invite all of the camp's detainees to the Berlinale red carpet. The film is one of 19 entries vying for the Golden Bear at this year's festival, which has been dominated by political themes.