Janet Fife-Yeomans, Sydney – The former head of Australia's spy network has revealed he never had any doubt Indonesian forces deliberately killed five young Australian newsmen in a "cover-up".

Gordon Jockel, who led the Joint Intelligence Organisation, said he had always assumed the newsmen were shot dead in Balibo so they could not expose the clandestine border raids by Indonesia into East Timor.

He told the inquest into the newsmen's deaths the tragedy could have been avoided – if Australia's intelligence agencies had spoken to each other.

He told Glebe Coroners Court that while all the facts that could have saved their lives on October 16, 1975, were known, no single agency pulled them together.

Former prime minister Gough Whitlam had warned one of the newsmen, Channel 7 reporter Greg Shackleton, not to go to East Timor. Australia's then ambassador to Indonesia, Richard Woolcott, had sent cables to the then federal government before the killings saying Indonesian raids on the area were imminent.

And among the 30 years of secrets uncovered during the inquest is the fact that intelligence radio intercepts of Indonesian military radio traffic confirmed the Indonesians knew the newsmen were in the Balibo area before they attacked the town.

Mr Jockel blamed divisiveness and isolation between government departments for the information not being shared.

Mr Shackleton, 27, Channel 7 cameraman Gary Cunningham, 27, sound recordist Tony Stewart, 21, Channel 9 cameraman Mr Peters, 29, and reporter Malcolm Rennie, 28, were killed.

"It seems to me that when you have a crisis of this nature, our authorities need to be more flexible," said Mr Jockel, now retired.