New documentary I am Chut Wutty, screened publicly for the first time on Tuesday, features previously unseen footage and interviews that tell the story of the anti-logging campaigner

In November 2011, Chut Wutty was campaigning with environmental activists in Prey Lang forest when he was attacked by military police – wrestled to the ground while he was burning illegally cut logs so that nobody could profit from them. Less than a year later, he was shot dead.

Wutty’s case, and the wider struggle of the Prey Lang activists who campaign against illegal logging, was broadcast before a London audience on Tuesday in the preview screening of I am Chut Wutty, a new documentary by environmental researcher and filmmaker Fran Lambrick.

The film, which was screened at independent journalism organisation the Frontline Club, is a 57-minute study of the Prey Lang network’s fight against the deforestation that takes place on an industrial scale. Since 2007, the 330 villages that fall within the bounds of Prey Lang forest – stretching across Kampong Thom, Preah Vihear, Kampong Cham, Kratie and Stung Treng provinces in the north of the Kingdom – have joined together to combat loggers.

Lambrick, 28, started work on the film three years ago, before Wutty’s death, as a project to complement her PhD in community forestry in Prey Lang. It was initially intended to be a study of the rapidly changing lifestyle of local people, but ended up taking a different turn when she came across the local activist group, she explained in London a few days before the screening.

“I became really interested in their work and the activism they do – they directly try to stop illegal logging by burning cut timber. I found them really interesting and inspiring because they were taking things directly into their own hands and saying, ‘We’re not going to put up with this.’ The whole film changed really the day we met them, because we decided to go on one of their campaigns,” she said.

How dangerous the work was dawned on Lambrick on that day in 2011, when the protesters were beaten by military police. “At that point, the film shifted from being more observational to having an element of real drama, showing the conflict and what an impact it has – the violence involved,” she said.

Wutty also believed things changed that day, she added. “Wutty said afterwards that for some of the activists, it really opened their eyes because of the violence that was meted out by these armed police officers against unarmed local people,” she said.

Environmental activists in the Kingdom regularly face harassment from authorities that can range from monitoring communications and movement and breaking up meetings to threats, intimidation, beatings and trumped-up court charges, said Josie Cohen, a land rights campaigner for Global Witness who was present at the screening in London.

“The courts are not independent and, alongside the military police, are used by the corrupt government to quell resistance,” she said.

Including Wutty, at least 13 environment and land defenders have been killed in Cambodia since 2002, according to Global Witness. Ten of these have been land rights activists; three – including Wutty – of them campaigning for forests.

A Global Witness report released earlier this year revealed that nearly three times as many environmental activists were killed worldwide in 2012 than 10 years previously. The 908 or more activists killed across 35 countries between 2002 and 2013 resulted in just 10 convictions.

The film handles Wutty’s death – and the impunity that followed - tastefully. Lambrick interviews Olesia Plokhii, one of two local journalists who was with Wutty when he was killed en route to a protected forest in Koh Kong. Her account is intercut with an animated re-enactment of what she experienced.

After Wutty was shot dead, military police officer In Rattana was also killed by a bullet. Ran Boroth, a security guard for the Timbergreen logging firm, eventually sentenced to two years in prison for Ratana’s death, served just six months of his sentence.

“The military officer who reportedly shot him was also killed in the incident. The investigation and subsequent trial were flawed, lacked credibility and only created further confusion around Chut Wutty’s murder. His family deserve much, much better,” Rupert Abbott, Amnesty International’s Deputy Asia Pacific Director, said in an email earlier this week.

Scenes with Wutty’s family after his death offer some of the film’s most poignant moments. Towards the end, we are offered a glimpse of their life now, without a husband and father. Sam Chanty, Wutty’s wife, remembers the day they met, when she was selling crushed ice and fruit at the market. His son, Cheuy Oudormreaksmey, tells us he used to beg Wutty to let him join him in the forest, but was never allowed – for his own protection.

“[Wutty] was really an incredible person, and it was a real shame that other people won’t get to meet him – he was incredibly energetic and quick thinking, very passionate, very gentle in one way, but very clear and very strong and quite steely,” Lambrick said.

While activists swore to carry on after Wutty’s death, the film makes it clear: he was one of a kind. In one of the most memorable scenes of the film, he says, staring straight into the camera, “If I don’t do the work, no one else will do it. They are too afraid.”