BUSAN (AFP) ― When filmmaker Davy Chou began to research the history of Cambodian cinema he found the films themselves had almost vanished amidst the devastation of war but that memories were keeping them alive.

“The Khmer Rouge marched into Phnom Penh in 1975 and the film industry just simply vanished,” says Chou.

“But the wonderful thing to me was that everywhere I went, people would remember the movies. They had passed these stories down from generation to generation.”

The 28-year-old French-Cambodian was drawn into the story through a family connection. His grandfather Van Chann was a film producer in the 1960s and ‘70s, a time when the Cambodian film industry thrived.

When Chou decided to become a filmmaker in his early 20s he also began digging into the past.

The fruits of his labors can be found in the documentary “Golden Slumbers,” which had its world premiere this week at the 16th Busan International Film Festival, where it is competing for the main documentary prize.

Chou made his first trip back to Cambodia in 2008. His family had escaped the Khmer Rouge regime, which wiped out up to two million people through starvation, overwork and execution, by moving to France. His grandfather never made another film after 1975.

But through family connections and the help of the Internet, Chou was able to piece together what remained of the industry in Cambodia.

From the shadows came directors, actors and film fans, and in “Golden Slumbers” they walk Chou ― and his audience ― back through time.

“Most of the people had lost contact with each other completely,” says Chou. “Filmmaking was outlawed under the Khmer (Rouge) regime and the directors, producers, actors ― they all were either killed or left the country or moved on to other things. Films were totally forbidden.”

Chou’s film, through testimony of the likes of charismatic former director Ly Bun Yim, shows that in the early 1970s the Cambodian film industry was thriving.

By the time the Khmer Rouge forces took Phnom Penh in 1975 the industry was producing more than 20 films a year ― romances, the re-telling of old legends, all with the unique sounds of Cambodian pop music pulsing away in the background.

Chou interviews ordinary people who describe how the population gathered in cinemas to watch the latest movies ― even as the fighting raged.

Chou finds that one ancient, dilapidated movie theatre in Phnom Penh has become home to hundreds of impoverished squatter families and that the old people there still tell children stories plucked from memories of what they saw on the silver screen.

“For so many of these people the movies are very much alive, even though they had not seen them for decades,” says Chou. “They knew the plots, the actors and the complete story lines.”

It remains unknown whether the Khmer Rouge actively set about destroying the prints of the estimated 400 Cambodian films that existed until 1975.

“We think that maybe the prints were just left to rot or were thrown away,”

Chou says. “People were fearing for their lives so they just didn’t want anything to do with them.”

While Cambodia’s former ruler King Norodom Sihanouk had famously shot short films of his family and even produced a few features, most Cambodian filmmakers of the time were inspired by foreign movies or by helping French director Marcel Camus when he shot the romance “Bird of Paradise” (1962) in Cambodia.

Now, only around 30 scratchy versions of their work remain, copied over the years from video to VCD and sold in the Cambodian communities which spread out across the world as people escaped the atrocities of the Khmer Rouge.

But, with the help of the Cambodian government, the country’s film industry is once again finding its feet thanks to a new film commission and funding for young filmmakers.

Chou has played his part too. Inspired by the history he found, he staged the Golden Reawakening festival and exhibition in 2009 and has helped set up the Kon Khmer Koun Khmer, a collective of young Cambodian artists.

“I think ― and I hope ― that in the end what this film shows is the power of cinema,” says Chou. “Even though these people had everything taken away, they still remember and they can still share those memories.

“To me that is truly inspirational.”