PHNOM PENH: A UN-backed tribunal in Cambodia has charged Khieu Samphan, former head of state for the Khmer Rouge, with genocide. The move came after genocide charges were filed against two other Khmer Rouge leaders, Ieng Sary and Nuon Chea.

All the genocide charges relate to the men's treatment of Cambodia's Vietnamese and Muslim minorities. All three men had already been charged with war crimes and crimes against humanity. Those charged are already in pre-trial detention although the trial is not expected to begin before 2011. Khieu Samphan, 78, has never denied the deaths, but both he and his lawyers insist that, he was never directly responsible. One member of his defence team is the infamous French lawyer Jacques Verges, whose previous clients have included Nazi war criminal Klaus Barbie and Venezuelan hijacker Carlos the Jackal.

Verges, 83, has known Khieu Samphan since they were both involved in left-wing student activities in France in the 1950s.He says he has lived a life of poverty after the Khmer Rouge regime was toppled.

A court official confirmed that the allegations were related to the treatment of two minority groups: Cham Muslims and ethnic Vietnamese people.

Researchers believe that the Khmer Rouge killed hundreds of thousands of Chams because of their religious beliefs. Final arguments were heard last month in the trial of Khmer Rouge prison chief Kaing Guek Eav, known as Comrade Duch, who has admitted being responsible for overseeing the deaths of 15,000 people. Judges at the tribunal are expected to make a ruling on his verdict early next year.