Israeli-Australian Mossad agent Ben Zygier did not give up any information to members of Australia’s internal security service, Canberra Attorney General Mark Dreyfus said Friday, denying reports the spy had been jailed for passing Israeli secrets to the ASIO.

Zygier, known until recently as Prisoner X, hanged himself in a super-secure jail cell in Ayalon Prison in 2010. Last week, Australia’s ABC television reported that Zygier, a Melbourne native who moved to Israel in 2000, was the mystery prisoner and earlier this week reported that Zygier had been arrested by Israel for passing information on Mossad use of Australian passports and on a Mossad operation to Australia’s internal spy agency.

Dreyfus’s spokesperson told the Sydney Morning Herald that the ABC report on why Zygier was arrested was incorrect.

“As often happens in cases of this nature, speculative material has found its way into the public domain,” she told the paper.

The attorney general’s office issued a statement after Dreyfus met with the ASIO head, backing up Prime Minister Benjamin Netanyahu’s statement earlier this week that Israeli and Australian intelligence agencies work together “with complete transparency.”

The Attorney-General has been fully briefed by the director-general of ASIO on his agency’s knowledge of this case,” the statement read, “The director-general’s account is entirely consistent with the recent statement issued by the Israeli Prime Minister.”

Israel has not commented on why Zygier was arrested, but said the case needed to be kept under wraps for national security reasons.

According to the ABC report, Zygier was jailed in early 2010 after the Israel feared he had passed information on a much-planned Mossad operation in Italy to the ASIO.

Earlier this week former foreign minister Alexander Downer said Zygier’s offense was likely much more serious.

Australian Foreign Minister Bob Carr originally said Zygier’s case had not been known to his office, but later flip-flopped and ordered an investigation into the Department of Foreign Affairs and Trade’s handling of the case.

Dreyfus said last week such an investigation was unnecessary.