AFP -  Khmer Rouge prison chief Duch admitted responsibility for his crimes at his UN-backed trial Tuesday and asked the families of the regime's victims for forgiveness.

"May I be permitted to apologise to the survivors of the regime and also the loved ones of those who died brutally during the regime. I ask not that you forgive me now, but hope you will later," Duch told the court.

"As a member of the (Khmer Rouge) I recognise responsibility for what happened at Tuol Sleng," he said, speaking in the Khmer language.

Duch's defence team asked that he be allowed to address the court after prosecutors spent the morning outlining their case against him for war crimes, crimes against humanity, torture and premeditated murder.

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?

But while the former prison chief expressed his regrets for running the detention centre which killed up to 15,000 people, he also insisted that he did not hold a senior role in the 1975 to 1979 regime.

"I was in a life and death situation for myself and my family," he said.

He went on to show an illustration he drew of the senior Khmer Rouge leadership structure, with Pol Pot as its leader and Nuon Chea, another current detainee at the court, as the deputy. Pol Pot died in 1998.

After Duch finished speaking, his defence lawyer Kar Savuth said by prosecuting Duch, the trial was not living up to its commitment to take on those most responsible for the crimes of the regime.

"How can justice be done and how can the victims who survived accept this?" Kar Savuth said.

"Duch is being prosecuted as a scapegoat on behalf of the other 195 chiefs of prisons. Please consider that fact."

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.