Cambodia’s UN-backed war crimes tribunal resumed the trial of the senior Khmer Rouge leader Duch on Monday.

On Monday, the former maths teacher politely answered questions to identify himself and heard charges crimes against humanity, war crimes, torture and homicide while serving as Tuol Sleng prison’s chief in the 1970s. 

Kaing Guek Eav, aged 66, is accused of overseeing the deaths of 15,000 people at the S21 prison.He is one of the first figures from the 1975-79 Khmer Rouge era to face trial. The trial started with procedural hearings in February 2009.

Find more reports, photos and live coverage on FRANCE 24: Interview with Jacques Vergès, lawyer for former Cambodian President Khieu Samphan. France 24's "Reporters" series on the Khmer Rouge trials. S-21 torturer faces new charges Web News: Reactions to Duch's trial Report: Torturer and victim meet, 30 years on THE OBSERVERS: Is it time up for the Khmer Rouge?

During Duch's tenure, thousands of inmates were taken from the Tuol Sleng prison, also known as S21, for execution at nearby Choeung Ek, an orchard now known as the "Killing Fields." 

Duch was found working as a Christian aid worker in the jungle in 1999, when he was detained. The war crimes tribunal formally arrested him in July 2007 and indicted him in 2008. 

“After 10 years in preventive detention, he will finally get an opportunity to express himself publicly and respond to the judges’ queries,” Duch’s French lawyer François Roux told FRANCE 24 in a telephone interview on Monday. 

Duch faces a maximum term of life in prison by the tribunal, which does not have the power to impose the death penalty. 

Four other senior figures of the Pol Pot regime have also been indicted, but no dates have been set for their trials. 

Up to two million people died of starvation, overwork or execution under the brutal Khmer Rouge regime, led by Pol Pot. 

For many Cambodians, the trial is is the last chance to find justice for the Khmer Rouge's crimes but according to FRANCE 24’s Cyril Payen in Phnom Penh, most of the Cambodian population is unaware of the trial.

The five prosecuted Khmer Rouge leaders Kaing Guek EavAFP This 66-year former maths teacher was the head of the Tuol Sleng, S.21, interrogation centre. Ieng ThirithAFP Charged with the 'planning, direction, coordination and ordering of widespread purges', the former Khmer Rouge minister of social affairs was also the wife of Ieng Sary. Ieng SaryAFP Foreign minister and then prime minister of the Khmer Rouge. He also led the guerilla war after the fall of the regime. Khieu SamphanAFP Head of state at the time of the Khmer Rouge, he founded the deadly revolutionary organisation Angkar. Nuon CheaAFP Known as 'Brother number two', he was the ideologist behind the Khmer Rouge regime.