The president of the Cambodian Independent Teachers Association has said he plans to screen a controversial documentary about murdered trade unionist Chea Vichea at the city’s newly-opened “Freedom Park”.

Who Killed Chea Vichea?, a 2009 film suggesting the outspoken Free Trade Union leader was killed for his activism, has been barred from being screened publicly in Cambodia, but CITA President Rong Chhun said he would attempt to screen it after Independence Day.

“We’re showing this film because we want people to know who killed Chea Vichea,” he said. “We want the government to investigate this case and punish the killer.”

Two suspects, Born Samnang and Sok Sam Oeun, were tried and convicted for Chea Vichea’s 2004 murder, though their convictions were later overturned. Government officials say investigations are ongoing.

Rong Chhun said he would inform City Hall about the screening on Wednesday. Phnom Penh Municipal Governor Kep Chuktema, who inaugurated the Freedom Park last week, could not be reached for comment.