A United Nations-backed tribunal in Cambodia has begun an investigation into the genocide known as 'The Killing Fields' in which an estimated 1.7 million people died in the 1970s.

The investigations got under way as Cambodia's former king Norodom Sihanouk rejected efforts to try only a handful of 'old, sickly, unrepentant individuals', saying the money would be better spent fighting poverty.

International prosecutor Robert Petit from Canada and Cambodian prosecutor Chea Leang are leading the joint investigation to determine which of the former leaders should face trial.

17 Cambodian and ten UN-appointed foreign judges were sworn in on 3 July, marking the beginning of a long-awaited tribunal that should see some former Khmer Rouge leaders tried by mid-2007.

Mr Petit warned Friday that it could take months to issue any indictments.