Jerusalem (CNN) -- An Australian-Israeli dual citizen who died in an Israeli prison gave Australian intelligence details of his work with Israel's Mossad before his arrest, an Australian television network reported Tuesday. The fate of the man dubbed "Prisoner X" is now the subject of an investigation by Israel's parliament. Prime Minister Benjamin Netanyahu pleaded over the weekend for details to be kept quiet, warning "overexposure of security and intelligence activity" could harm Israel's security. But the Australian Broadcasting Corporation has identified him as Ben Zygier, and it reported Tuesday that he had reported "every aspect of his work" for the Mossad, Israel's spy agency, to the Australian Security Intelligence Organization.
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NEW: Australian network says 'Prisoner X' shared Israeli secrets with Australia
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The man died in an Israeli cell in December 2010; details have not been released
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Israeli lawmakers say they're investigating the case
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Netanyahu warns against "overexposure" of intelligence work
He met with @placeholder intelligence during a trip back to Australia, ABC reported.