The grave of Ben Zygier (L), the Australian whom local media have identified as the man who died in an Israeli prison in 2010 and who may have been recruited by Israeli intelligence agency Mossad, is pictured at a Jewish cemetery in Melbourne.

Sydney -

Canberra knew for almost a year that Israeli authorities were detaining Melbourne man Ben Zygier, Foreign Minister Bob Carr said on Thursday.

Zygier, a Mossad spy accused of “treason,” was arrested in February 2010 and found hanged in his cell December 15 that year.

Carr had earlier denied that his office had any knowledge of Zygier until notified of his apparent suicide at age 34.

Zygier, a lawyer who left Australia for Israel in 2000, is presumed to be the mysterious “Prisoner X” who was kept in secret isolation inside an Israeli jail.

He had served in the Israeli military before taking a law degree at Melbourne University.

“The Australian government was informed in February 2010 through intelligence channels that the Israeli authorities had detained a dual Australian-Israeli citizen,” Carr told a parliamentary committee.

According to reports aired on Israeli Army Radio, Zygier, the son of a well-known Melbourne Jewish family, was being held for “treason” in the maximum-security Ayalon prison.

“The Israeli government further advised the Australian government that the individual would be treated in accordance with his lawful rights as an Israeli citizen,” Carr said. “The Australian government relied on these assurances.”

The foreign minister said the Australian government had not received a request for consular assistance from Zygier's family and so had not interceded on his behalf.

Carr has ordered a review into the handling of a case that came to light only through a probe by national broadcaster ABC.

The ABC reported on Tuesday that Zygier, who married Israeli woman Maya Zalewski and fathered two children with her, was the Prisoner X.

The report said Zygier had changed his name to Ben Alon and the Foreign Affairs Department said he had taken out a passport in the name of Ben Allen.

The ABC reported that his body was flown to Melbourne seven days after his death and is buried in Chevra Kadisha Jewish Cemetery.

Family and friends refused to speak to the ABC.

Carr could not say whether Defence Minister Stephen Smith, who was foreign minister at the time of Zygier's arrest, was told of it.

The Australian newspaper said Zygier's detention ran parallel with a spat between Israel and Australia over Mossad's methods.

In May 2010 Smith expelled Mossad's station chief in Canberra after Mossad was found to have forged the Australian passports of four dual nationals.

The passports had been used in what is believed to be an Israeli operation to assassinate Islamist Palestinian group Hamas leader Mahmoud al-Mabhouh in Dubai in January 2010.

The paper said it did not know whether the two cases were linked. - Sapa-dpa