A documentary about the brutal Communist purges in Indonesia under dictator Suharto will premiere in Berlin this weekend before it heads towards Asia in March.

Since it premiered at the Toronto Film Festival last year ‘The Act of Killing’ has inspired debate on social media around the impact of the 1965 mass killings, while raising questions about the governance of modern Indonesia.

Film festival accolades were led by luminaries such as renowned documentary film-maker, Werner Herzog, who said he’d not seen a more powerful, surreal and frightening film in the last decade and called it “unprecedented in the history of cinema”.

A scene from The Act of Killing movie.

After the military coup that brought him to power, Suharto set about wiping out Communist Party supporters through his loyal army and affiliated paramilitaries.

The film follows a group of former ‘gangsters’ who were members of Suharto’s paramilitary ‘death squads’. Between them, they helped the army kill more than a million Communists, ethnic Chinese and intellectuals in less than a year following the military coup of 1965.

Shot over the course of seven years, ‘The Act of Killing’ hones in on two ringleaders, Anwar Congo and Adi Zulkadry, who went from selling black market movie theatre tickets to interrogating and murdering hundreds of innocent people.

Director Joshua Oppenheimer recruited the men, all fans of genre movies, to star in their own production about their crimes: they wrote their own scripts, and played the roles of themselves and their victims.

In one scene Anwar dances on a rooftop where he killed dozens of innocent people using razor wire. His friend, Adi, chuckles in disbelief as he describes a killing spree where he stabbed ‘dozens’ of Chinese people in one street before attacking the father-in-law of his Chinese girlfriend.

As each of the perpetrators relive their gruesome past – through their film – the consequences become severe.

The film also parades some uncomfortable realities about modern governance in Indonesia – everyday corruption, vote rigging – ministers, paramilitaries and governors all have jaw-dropping walk-on parts, shaking hands with the former death squad members and lauding their work as a national duty.

“Those who took part in the killings were widely seen as having done Indonesia a service, however repulsive they might be as individuals,” says Australian National University’s Professor Robert Cribb, an expert in the Communist purges in Indonesia.

He says that some kind of legal reckoning or reconciliation process – which the film touches on – would be near impossible to enact.

“Basically the killers were part of something bigger and that something bigger had two (or more) sides. I’m not sure that a legal reckoning now would be anything more than another kind of victor’s justice,” he says.

“Every possible action – including inaction – has pretty serious moral complications, and I really don’t see a simple solution in Indonesia’s case.”

2012 was a vintage year for documentaries with standouts such as ‘The Imposter’ and ‘Searching for Sugarman’, both shortlisted for this month’s Oscars.

The Act of Killing will be eligible for next year’s Oscars and after its European premiere this weekend it will be making its way back to Asia with strong support from Indonesians, who have been waiting for the truth to come out.

The Communist purges have never been publicly discussed in Indonesia. School children don’t learn about the events of 1965, textbooks depict the killings as the work of patriots that resulted in less than 80,000 deaths.

Currently all films for public distribution in Indonesia are vetted by the national censorship board, but fans of ‘The Act of Killing’ have been behind its word-of-mouth success.

Audiences have attended invite-only screenings at small venues around the country; they also rallied when its website mysteriously went down earlier in the year.

Screenings of the documentary have been lined up in Singapore and the Hong Kong International Film Festival in March. It will also feature at the annual Sydney Film Festival in June.