|Vann Nath's life was spared only by painting portraits of Khmer Rouge leader Pol Pot [EPA]
Vann Nath, a Cambodian painter whose life and art were powerful symbols of the county's struggle to overcome the horrors of the Khmer Rouge era, has died at a private hospital in Phnom Penh.
He was 66.
Vann Nath was one of only seven known living survivors of S-21 prison, known as Toul Sleng, in Phnom Penh.
Of those seven, he was believed to be one of the last three living survivors when he passed away on Monday.
Between April 1975 and late 1978 up to 16,000 people were tortured at the former school before being taken to the killing fields outside the capital and executed, most often with a blow to the back of their neck.
Vann Nath was spared because he was ordered to paint and sculpt portraits of Pol Pot and other leaders of the regime that killed as many as two million Cambodians due to starvation, overwork or execution in a bid to create an agrarian utopia.
After the fall of the Khmer Rouge to Vietnamese forces in 1979, Vann Nath was freed and went on to paint vivid images of the atrocities he witnessed under the Khmer Rouge. These paintings are now considered some of the most important visual documents of modern Cambodian history.
Van Nath's 1998 memoir, A Cambodia Prison Portrait: One year in Khmer Rouge's S-21 prison, is the only written account by a survivor of Toul Sleng.
Vann Nath, who struggled for years with ill health including kidney problems, had been in a coma since suffering a cardiac arrest on August 26, his son-in-law told the AFP news agency.
Tuol Sleng is now a genocide museum and many of Vann Nath's works adorn its walls, depicting torture methods such as prisoners being whipped and having their fingernails pulled out with pliers.
In June 2009, he became the first survivor to testify the Khmer Rouge trials, Cambodia's UN-backed war crimes court, in the trial against Tuol Sleng jail chief Kaing Guek Eav, alias Duch.
Duch was sentenced to 30 years in jail last year for war crimes and crimes against humanity. The case is now under appeal with a ruling expected later this year.
Lars Olsen, the tribunal spokesman, told the AFP news agency the court was "saddened" by the death of Vann Nath, "who gave a voice to victims both through his testimonies before the court and through his lifelong work at Tuol Sleng museum".
"Brother Number One" Pol Pot died in 1998 without ever facing justice.
Vann Nath is survived by his wife, two daughters and a son. A Buddhist ceremony will be held at his home in Phnom Penh.