SYDNEY: Australian intelligence had detailed knowledge of the case of a Melbourne man thought to have been an Israeli spy well before he died in a Tel Aviv jail in 2010, a report said Saturday.

"Every day that goes by you see how deeply involved they were," a senior Israeli official told The Australian newspaper. "It is clear they were in the know long before he died."

The unnamed source told the paper that Australian officials had suspected the man known as "Prisoner X" of spying for Israel and had interrogated him, adding "they (the Australians) knew many things".

"Then, when the coffin was returned to Australia, they knew he was not some backpacker who got lost trekking," the official said.

An Israeli probe into the death in December 2010 of the prisoner identified in Australian media as Ben Zygier, a 34-year-old Australian Jew recruited by Israel's Mossad spy agency, found he had committed suicide.

But a justice ministry official told Israeli journalists the judge handling the case has demanded a further probe "to examine issues of negligence".

The fact that the detainee, held in a high security prison under continuous surveillance, managed to hang himself has raised questions and fed conspiracy theories that have been reported by the Israeli and Australian media.

Many questions remain unanswered in the mysterious case and Zygier's family has not commented since the Australian Broadcasting Corporation broke the story naming him as Prisoner X last week.

Australian journalist Jason Koutsoukis, who interviewed Zygier several times in 2010 while working for Australia's Fairfax Media, said the Melbourne-raised lawyer who moved to Israel in about 2002 had vehemently denied spying.

Australia's Foreign Minister Bob Carr said last week he was troubled by Zygier's death but could do little without a complaint from the family.

Carr, who only became foreign minister in early 2012, had earlier said he had been told there was no record of contact between the prisoner's family and the Australian embassy in Tel Aviv or the Department of Foreign Affairs in Canberra.

"So on my advice, the Australian government was not informed of his detention by his family or by anyone else," he told the ABC.

Carr has since admitted that Canberra was informed in February 2010 -- 10 months before Zygier died -- that Israel had detained an Australian-Israeli citizen on national security grounds.

He has since ordered a review of Australia's handling of the case.

Carr said Canberra had sought assurances at the time that the detainee's legal rights would be respected and that he was not being mistreated.

"At no stage during his detention did the Australian government receive any request from the individual or his family to extend consular support," he added.

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