Dir: Rithy Panh. France. 2003. 101mins

A sincere and honourable attempt to fathom the depths of human evil, documentary S21: The Khmer Rouge Killing Machine offers eyewitness testimony to the painstaking system of torture and repression that existed in Cambodia during the 1970s. The film returns victims of the regime and their former torturers to a notorious detention centre, and director Rithy Panh uses their painful memories and broken lives to build a detailed picture of a reign of terror administered, which ruled with all the efficiency and ruthlessness of a successful modern business.

An act of remembrance and a small step towards reconciliation, the film is an ambitious first move in laying to rest some ghosts from the past. Tightly focused and a little repetitive in the ground that it covers, it might secure some specialised theatrical interest but has a brighter future in festival screenings and small screen exposure.

An all too brief initial chronology of events in Cambodia provides a vital context to the scenes that follow as we are reminded that almost two million people died during the four year reign of the Khmer Rouge between 1975 and 1979. Towns were evacuated, currency was abolished and people were arbitrarily imprisoned and executed for fabricated crimes against the state.

S21 was the main Security Bureau in the heart of Phnom Penh, which has now been converted into a Genocide Museum. Some 17,000 prisoners were tortured, interrogated and executed at S21. Painter Vann Nath is one of only three men who survived the experience and the core of the film is his brave, dignified quest to face his former torturers and search for an understanding of their actions.

Confronted with photographs, old records and endless documentation, the men recall a vast bureaucratic system for administering torture. There are hair-raising tales of the disregard for human life as people were drained of blood, tortured to obtain false confessions and provided with only enough medical care to keep them well enough to be tortured again. Petty infringements were punished mercilessly and suicide was the ultimate act of defiance. They also provide chillingly-animated recreations of the way the Khmer Rouge would undertake the minutiae of their daily duties as they exercised absolute power over thousands of innocent lives.

The sheer weight of testimony makes for compelling and uncomfortable viewing, but S21 remains the kind of documentary that asks more questions than it can ever hope to answer. The former torturers discuss their past actions with a stunned sense of shame and embarrassment as if they had merely dishonoured themselves or their families. Nobody takes responsibility for their actions.

Mass murderers hide behind a well-worn defence of merely having followed orders. There is no urgency to atone for their sins and no expressions of remorse. Their greatest motivation appears to have been self-preservation and a misguided loyalty to a party that demanded unquestioning obedience. Any vestige of compassion was subsumed within that loyalty and anyone looking to make sense of this particular situation or the wider issue of genocide is still left asking how this could have happened.

Prod co: INA, Arte France
Int'l sales: TBA
Exec prods: Liane Willemont, Aline Sasson
Prod: Cati Couteau
Cinematography: Prum Mesar, Rithy Panh
Ed: Marie-Christine Rougerie, Isabelle Roudy
Music: Marc Marder