The book he wrote in 2001 on his experience, 'The Gate', has been recently published in English.
He talked to the BBC's East Asia Today programme about his horrific ordeal, and his relationship with his interrogator, the notorious Khmer Rouge leader known as Duch.
Mr Bizot was working as an anthropologist in Cambodia when he was arrested by the Khmer Rouge in 1971 and detained for 90 days in a jungle camp.
During that time he was interrogated daily by Duch, a Khmer Rouge cadre whose real name was Kang Kek Ieu.
Duch later became the chief interrogator at the infamous Tuol Sleng torture camp.
An estimated 1.7 million people died under the Khmer Rouge's rule, many of them in camps like Tuol Sleng.
But Mr Bizot told East Asia Today that during his incarceration, he developed a close relationship with Duch.
Idealism
The fact that he was eventually freed he attributes partly to Duch's idealism.
"He was a truth seeker... he was looking for the absolutes in life, and he was very aware of injustice," he told the BBC's East Asia Today programme.
"
What I learnt from Duch and the torturers was that, altogether the good and the bad are in ourselves
"
Francois Bizot
"When I saw the killer's mask drop from him, what I saw behind the mask was not a monster...I saw someone looking like myself."
After three months of interrogation, Bizot was freed.
He left Cambodia, but the experience stayed with him.
When asked what he had learnt from the experience, he said: "We will never progress if we try and divide humanity into good and bad."
"What I learnt from Duch and the torturers was that, altogether the good and the bad are in ourselves."
Cambodia has still not recovered from the genocide of the Khmer Rouge era.
Several senior Khmer Rouge leaders still live freely.
Only two are in detention, including Duch.
But correspondents say that the government seems unable- or unwilling - to bring them to trial.