STORIES go in and out of focus in the news, eventually hardening into history, and yet history can be misleading. In the argot of today, Siberian prison camps are, like, so yesterday, but the truth is different.

Although officially disbanded in 1960, the legacy of Stalin's Gulag lives on beyond frozen memories of 12 million mainly political prisoners being sentenced to Siberian banishment in the 1950s. There are still 135 camps in the Siberian region of Kransnojarsk, housing a free labour force of a million prisoners.

Belgian photographer Carl De Keyzer was granted access to document life in 35 camps over two years, although the word "access" needs qualifying. The authorities were at his shoulder, always seeking a positive spin and trying to stage-manage scenes, be it placing a Bible prominently on a bed or delaying his entry to a camp until a hasty lick of paint had been applied and prisoners were issued with crisp new prison-wear.

The skill of the documentary photographer is to remove the veneer, and Keyzer's technique is not so much to scrape away at the surface as to apply the tactics of stealth. On the one hand, he presents the everyday, the daily lunch of bowls of sardines and blocks of bread and the graft of Zona life (zona is Siberian slang for prison) as bare-chested prisoners hack away at stone on a hospital construction programme.

On the other hand, he breaks free of those carefully tended boundaries to suggest a more sinister regime. Beyond wary expressions of repression and isolation are more absurd images: two men playing tennis without balls, huge statues for the inter-camp ice sculpture competition; a woman in a bearskin in the summer sun (she is fighting off the flu).

Most haunting is a frostbite victim's stump of an arm, newly amputated after he had fallen asleep in temperatures of minus 40C while he was on a vodka binge.

Impressions Gallery's exhibitions are often at the cutting edge of photography, exploring new technology. However, Zona is reminder of the power of documentary photography to inform, shock and educate.

Updated: 10:35 Wednesday, March 16, 2005