Director Rithy Panh was 15 when he escaped the horror of a Cambodian labour camp under the communist Khmer Rouge. He never saw his parents or his sisters again.
His film "The Missing Picture" attempts to tell their story, from life before their incarceration to when they were caught up in the Khmer Rouge's merciless 1975-79 rule.
The film has become Cambodia's first ever to be nominated for an Oscar, making the short list in the Best Foreign Language Film section at the Academy Awards to be announced in Los Angeles on March 2.
"It is important to me, as a survivor, that we do not forget what has gone before us and the people who lost their lives," said Panh, 50, on the phone from Phnom Penh.
"'The Missing Picture' has two meanings -- one is about a real story that we remember and another is about what (pictures) we never see."
The Khmer Rouge sought to transform Cambodia into its vision of an agrarian utopia, which led to the deaths of up to two million people from starvation, overwork, torture or execution.
As well as his parents and sisters, Panh lost 10 members of his extended family during the Khmer Rouge's reign. "I cannot count all my cousins, aunts, uncles," he said.
"The second 'missing picture' is about my personal story. I regret that I do not see my father nowadays. If he was alive, maybe I would take him for a walk along the riverfront, or for meals. I cannot have this kind of experience."
As the reign of the Khmer Rouge in Cambodia was nearing its end, and Vietnamese forces began entering the country, Panh fled from his distracted captors, making his way first to an internment camp in Thailand and then on to Paris.
He eventually turned to film as a means to deal with his past, studying at L'Institut des hautes études cinématographiques.
He returned to Cambodia in 1990 and developed a series of feature films and documentaries – including "One Evening After the War" (1998) and "S-21: The Khmer Rouge Killing Machine" (2003) – which told the stories of people caught up on either side of the terror.
"The Missing Picture" uses footage from the period -– mainly propaganda films -- and clay dolls where material is missing to recount the horrors.
The special effects were driven by necessity. Cambodia’s film archives, which dated as far back as the late 1800s, were left mostly destroyed by the Khmer Rouge. Panh has dedicated his life to seeking out and restoring lost films he believes tell the story of his country.
Panh has been one of the driving forces behind the Bophana Audio Visual Resource Centre in Phnom Penh, which opened in 2006 and aims to preserve the country’s aging film stock, along with recorded radio transmissions, newsreels and photos.
Because of the Oscars "a lot of people will be talking about this film, so we want to use that to get them to talk about Cambodia," said Panh.
"Maybe people can decide to help us to save the films we have found, and help us continue our work."
"The Missing Picture" won the Un Certain Regard section at the Cannes Film Festival last May while Panh's work towards restoring Cambodia's film archive was acknowledged at the Busan International Film Festival in October, where he was named Asian Filmmaker of the Year.
The Bophana centre aims to educate a new generation of Cambodian filmmakers while holding regular screenings of recovered footage.
"Cambodia has a rich history that is not only about the Khmer Rouge – they were only here for four years. We want people to know our whole story and film helps do that."
As the international film industry increasingly turns to digital technology, the director fears the skills – and equipment – needed to restore old film stock might soon be lost.
"Time might be running out for us and we need as much help as we can get," said Panh.
"Film technology is changing so we need to act as soon as possible," he said. "As the industry goes digital it will become harder for us to restore old films. The big challenge in the future might be how people will access these films, and access their own memories."
The filmmaker says he feels it is his responsibility as a survivor to make sure that the past is acknowledged and accepted.
"I am here because those who died helped me to be here," he said.
"My films are a tribute to them. This is a way that their dignity is returned to them."