A film about the Cambodia-Thailand border conflict at Preah Vihear that has courted controversy in Thailand will be screened at Meta House this evening.

The documentary Boundary by Thai filmmaker Nontawat Numbenchapol explores both sides of the conflict for a nuanced portrayal of the violence over the 11th-century temple.

In an interview at Meta House yesterday, Nontawat said he originally meant for the film to explore the Thai 2010 political crisis that culminated in a bloody crackdown against anti-government “red shirt” protesters in Bangkok in May of that year.

“Before I made the documentary, I was not interested in Thai politics, but at that time everyone in Bangkok was affected,” he said.

But his plans changed when he travelled to Sisaket province near the Cambodian border in 2011 to capture footage of a former Thai conscript who had taken part in the crackdown. Finding the border engulfed in tension, he interviewed the local Thai villagers caught up in the skirmishes between Thai and Cambodian soldiers.

Deadly clashes occurred periodically along the border from 2008 to 2011 after Preah Vihear temple was listed as a Cambodian UNESCO World Heritage site against Thailand’s wishes.

Nontawat said that when he looked back at the footage from his interviews, it appeared biased towards the Thai side of the conflict. He realised he had to cross the border to speak with the Cambodian villagers at Preah Vihear.

As the border was closed, he flew to Phnom Penh to find a guide to take him to the conflict zone. But finding a Cambodian willing to cooperate took him about a year as many assumed he was a spy.

Nontawat was finally able to access the Cambodian side of the story when a French-Cambodian filmmaker told him of a Cambodian woman he had met at a New York film festival who happened to be from a village along Preah Vihear’s border. The woman, who was happy to have a Thai filmmaker tell Cambodia’s side of the story, agreed to take him if he disguised his identity.

“I told everyone I was a friend from New York, a Chinese-American named Thomas,” he said with a laugh.

He found that Cambodians were angry with the Thais, accusing them of stealing their temple and afraid that they would even one day try to capture Angkor Wat.

But on the Thai side, he discovered that the locals were also angry with the Bangkok government for inflaming relations with Cambodia. The violence and subsequent border closure, he was told, caused great disruption to local commerce.

“Before they had good lives and everyone had friendships and good relationships with Cambodians. But when some people from Bangkok protested about [Preah Vihear] and the border was closed and there was a war, people who lived on the border had problems with their lives,” said Nontawat.

The film was temporarily banned in April 2013 by the Thai film censors, but the ban was rescinded shortly afterwards when the story was picked up by the international media.

Nontawat said: “It was the talk of the town, and everyone blamed the censors for being silly. They called me two days later, and they unbanned it. I think because of the power of democracy.”

Boundary will be screened 7pm tonight at Meta House followed by a Q&A.