Sydney – A telegram sent from a minister just days after the Balibo Five were killed in East Timor revealed they had been murdered, and proved the government was engaged in a cover-up, one of their widows says.

Shirley Shackleton received the communique from Whitlam era foreign minister Don Willesee days after her husband Greg and four other journalists were reported missing in East Timor in 1975.

In his dying days in 2003, Mr Willesee told his daughter the Australian government covered up the affair, The Australian newspaper reported today.

Mr Willesee's daughter Geraldine has written how her father talked bitterly and unforgivingly about Australia's role in the Indonesian invasion of East Timor.

His version of events is contrary to evidence given by former prime minister Gough Whitlam under oath at a Sydney inquest into the death of one of the Balibo Five, due to report its findings next week.

Ms Willesee said her father claimed the five journalists – Brian Peters, Greg Shackleton, Gary Cunningham, Tony Stewart and Malcolm Rennie – were "murdered" by Indonesian soldiers at Balibo in East Timor, not caught in crossfire as officially reported.

Mrs Shackleton said she received a lengthy telegram from Mr Willesee within the 10-day period in which the government was still reporting the journalists to be missing.

"It was long," she told AAP. "He said that he was very sorry, he mentioned that they were dead, which no one else had said. The only official information I received over those terrible 10 days was from him."

She said she never mentioned the telegram when asked to provide a written statement to the coronial inquest because she was sure any cover-up would plague the inquest.

"I didn't mention the telegram because it didn't occur to me actually, because it seemed that all that stuff with Willesee had been just thrown under the carpet and I was never going to be a witness," Mrs Shackleton said.

The inquest heard Mr Willesee was under pressure not to reveal how the men died, since the Australian military found out through an intercepted Indonesian military radio communication.

Mrs Shackleton said national security may have been an issue at the time, but a continued cover-up will mean the Australian government must have other motives.

"Listen, 32 years on, it can't affect our national security, so why haven't they come clean?" she asked. "And why do they lie – because of trade, because of money? That's what it's all about still."

Mrs Shackleton is sure Mr Willesee's revelations to his daughter are accurate because he was the first person to tell her the men were dead. "He even mentioned (in the telegram) he was terribly distressed because he had journalist children," she said.

Mrs Shackleton said she was later instructed to destroy the telegram. "I was given a lawyer, who I found out later was a big Whitlam fan, and he advised me to tear it up because it was distressing," she said.