Revealed at last: art film of an Afghan warlord's 'human dog'

Zardad's Dog, a film by the artists Ben Langlands and Nikki Bell, can now be shown after the warlord, Faryadi Sarwar Zardad, was jailed in July. He had escaped to Britain to claim asylum but was convicted of torture and hostage-taking in his homeland.

One of the stories told against him was that he kept a "human dog" - his armed guard Abdullah Shah - to savage captives. Shah was said to have a penchant for biting his victims then murdering them. Shah's trial in Kabul for killing more than 20 people including a mother and daughter is the story told in the Langlands and Bell film.

The footage was shot by the artists in the Supreme Court in Kabul in October 2002. It shows a packed and run-down courtroom presided over by armed guards. Only simple explanation is added, but the introductory religious blessing, the prosecutor's speech, the witness statements and the defendant are said to be readily understandable despite using an Afghan language.

The trial concluded in Shah's conviction and he was executed in April last year in what was the first capital trial in Afghanistan since the fall of the Taliban

The work was one part of Langlands and Bell's Turner Prize presentation at Tate Britain, The House of Osama bin Laden, which was the result of an intense two-week stay in Afghanistan commissioned by the Imperial War Museum in London.

Using still and video cameras, the artists recorded visits to sites including Bamiyan, where the giant statues of Buddha were destroyed by the Taliban, and a former home of Bin Laden at Daruntah.

But the Tate's lawyers advised the gallery that Zardad's Dog should not be shown while Zardad was facing what turned out to be his first trial in the UK. He was eventually convicted in July after a retrial at the Old Bailey. Zardad ran a pizza restaurant in Bexley at one stage and was living on benefits in Streatham, south London, when he was arrested in 2002. He had been tracked down by the BBC's John Simpson from information given by a Taliban minister in an interview three years before.

The warlord was the first foreign national accused of torture and hostage-taking to be tried in Britain under international law. Scotland Yard officers interviewed Abdullah Shah on death row during their investigations into Zardad's crimes. Shah was described as a huge, hairy man who seemed "quite deranged".

Visitors to last year's Turner Prize exhibition were alerted to the film's omission by a notice on the wall. It finally goes on display in the Lightbox space at Tate Britain on Monday until 3 November.

Langlands and Bell are London-born, the former in 1955 and Bell four years later. They studied fine arts at Middlesex Polytechnic and have been working together since 1978. They were beaten to the 2004 Turner by Jeremy Deller.