Alyssa Braithwaite, Sydney – The Australian government was forewarned that Indonesian soldiers disguised as civilians or anti-Fretilin troops planned to invade East Timor on October 16, 1975, an inquest has been told.

Five Australia-based newsmen were killed in an attack by Indonesian special forces troops in the Timorese border town of Balibo on October 16, 1975.

Official reports have maintained the journalists, Greg Shackleton, Gary Cunningham, Tony Stewart, Malcolm Rennie and Brian Peters, were killed accidentally in crossfire between Indonesian troops and Timorese militia. But their families insist they were murdered.

Alan Renouf, who was head of Australia's Department of Foreign Affairs in 1975, told a Sydney inquest into Mr Peters' death today the government had received a cablegram on October 13, 1975 from the embassy in Jakarta indicating Indonesian forces would move into East Timor within two days.

The department received a second cablegram on October 15, stating 3,800 Indonesian troops would advance into East Timor and Indonesian president Suharto would deny any involvement by Indonesian troops.

Mr Renouf said when the department learned of the journalists' deaths the common view was they had been deliberately killed.

"I don't think there is any doubt the responsibility for the killing of the five journalists lies with Indonesia," Mr Renouf said. "The killing of the five journalists was revolting, quite unnecessary, cold-blooded and really merciless. It was a wanton, infamous act."

A former officer with the Department of Foreign Affairs, James Dunn, told the inquest that a few months after the attack an East Timorese soldier who had been fighting with the Indonesian military confirmed to him the journalists had been murdered.

"He told me the journalists had been killed deliberately by Indonesian troops under the command of Cornel Dading Kalbuadi," Mr Dunn told the court via telephone.

"Of course if they had stayed alive they would have exposed what was a covert operation – Indonesian invasion." Mr Dunn said from his knowledge of the Indonesian military and his work as an intelligence officer with the Department of Defence, he believed orders to kill foreign journalists would have to have come from the top, or near to it.

He said the Indonesian government would have been aware the journalists were in Balibo as their presence in the small border town was "big news".

But Richard Woolcott, who was Australia's ambassador to Jakarta at the time of the Indonesian invasion, told the inquest news that there were Australians in Balibo didn't reach him. "If I had (known) I would have... urged something be done to get them out of that area," Mr Woolcott said.

Mr Woolcott received four boxes containing the remains of the journalists in November 1975 and helped conduct a funeral ceremony in Jakarta a month later.

But he said he knew nothing about a phone call Mr Peters' sister, Maureen Tolfree, received on landing in the capital in the hope of attending her brother's funeral.

The court was told Ms Tolfree was led to a room by four Indonesian soldiers, where she received a telephone call.

A man on the other end of the line, who did not have an Indonesian accent, said to her: "We cannot guarantee your safety and I advise you to get back on the plane and continue your journey."

The inquest continues tomorrow.