Life sentence demanded for Khmer Rouge prison chief

Prosecutors at Cambodia's UN-backed war crimes court have demanded an increased sentence of life imprisonment for a former Khmer Rouge prison chief who was jailed for 30 years in July.

Kaing Guek Eav, better known as Duch, was convicted of war crimes and crimes against humanity for overseeing the mass murder of 15,000 men, women and children at Tuol Sleng prison in the late 1970s.

Duch was initially handed 35 years, but the court reduced the sentence on the grounds that he had been detained illegally for years before the UN-backed tribunal was established.

"We are asking for life imprisonment, to be reduced for mitigating purposes to 45 years," Anees Ahmed, the senior assistant co-prosecutor, said after his team submitted their appeal document.

It is to compensate for the period of unlawful detention that the co-prosecutors are asking that a life sentence be reduced to 45 years with no parole.

"The co-prosecutors submit that a sentence of 35 years for crimes of this magnitude is plainly unjust," the appeal document read.

The co-prosecutors are also seeking additional convictions "for the crimes against humanity of extermination, enslavement, imprisonment, torture, rape, persecution on political grounds, and other inhumane acts", the document said.

Led by "Brother Number One" Pol Pot, the Khmer Rouge was responsible for one of the worst horrors of the 20th century, wiping out nearly a quarter of Cambodia's population through starvation, overwork and executions.