Mr Ramos Horta says the film is largely accurate
East Timor's President Jose Ramos-Horta has said five foreign journalists who died in Indonesia's 1975 invasion were tortured and shot by the military.
He made the allegation at the Melbourne launch of the film Balibo, which depicts their deaths as Indonesia's army crossed into East Timor.
Jakarta has always said that they were killed in crossfire with rebels, which Australian governments have accepted.
The film shows them being shot on the orders of Indonesian army officers.
Mr Ramos Horta was a rebel commander at the time and is a central figure in the film. He said he had looked into the deaths of the "Balibo Five" soon after they were killed in the border town of Balibo.
At the Melbourne premiere, he claimed the film was largely accurate, but that its makers were unable to convey the full horror of the killings because it would be too shocking for cinema audiences.
He said the journalists were not just killed by the Indonesian military but, as he put it, "brutally tortured".
Their bodies were burned to dispose of the evidence of their killings, he said.
Balibo is the first feature film to be shot in East Timor.
It tells the story of Australians Greg Shackleton and Tony Stewart, Britons Brian Peters and Malcolm Rennie and New Zealander Gary Cunningham - who were killed when Indonesian troops overran Balibo in October 1975.
The filmmakers have said that the official Indonesian and Australian view that they died in crossfire is absurd.
That film's version of events was validated by an Australian coroner in 2007.
After a fresh review of the evidence, the coroner ruled that the journalists had been killed as they tried to surrender to Indonesian forces.
The filmmakers are hoping that Balibo will spur the Australian government into action.
Almost 18 months on, it still has not given its response to the coroner's findings - a reticence which may stem from its fear of upsetting diplomatic relations with Jakarta, says the BBC's Nick Bryant in Sydney.
Indonesian troops invaded East Timor shortly after Portugal withdrew in 1975, ending 450 years as its colonial ruler.
At least 100,000 people are estimated to have died as a result of Indonesia's 25-year occupation, which ended with East Timor's independence in 2002.
At the Balibo premiere, Mr Ramos-Horta applauded the changes which had taken place recently in Indonesia.
"It is better. Indonesian democracy today is one of the most inspiring in the south-east Asia region."