Secret government files reveal that Australian governments, diplomats and spies have known for more than 30 years that Israel has an arsenal of nuclear weapons, while continuing to deny any knowledge of its existence to the point of misleading Parliament.
Previously secret diplomatic files declassified by the National Archives reveal a longstanding policy to turn a blind eye to Israel's nuclear arsenal. Last week the Department of Foreign Affairs and Trade again declined to comment on whether the Australian government thinks Israel is an undeclared nuclear weapons state.
Foreign Affairs Department briefing papers prepared for former Labor foreign minister Bill Hayden in 1987 state that ''intelligence assessments are that Israel has a small arsenal of nuclear weapons (possibly about 20). Israel's technological capabilities would enable it confidently to deploy such weapons without recourse to a nuclear test.''
In a confidential exchange with International Atomic Energy Agency chief Hans Blix on September 22, 1987, Mr Hayden ''commented that there appeared no doubt that Israel had nuclear weapons''.
Mr Hayden and Dr Blix were talking against the backdrop of the treason trial of Mordechai Vanunu, the Israeli nuclear technician who in 1986 disclosed detailed evidence of Israel's nuclear weapons production. The Foreign Affairs Department advised Mr Hayden to publicly deny knowledge of Israel's nuclear weapons capabilities. Mr Hayden told Parliament on September 17, 1987: ''We have no information to corroborate these allegations.''
However, Foreign Affairs' files, declassified in response to applications by Fairfax Media, reveal that Australia had been monitoring Israel's nuclear program from its beginnings in the 1950s.
Australia scooped US and British intelligence when in 1966 its Atomic Energy Commission obtained ''highly sensitive'' information from the French builders of Israel's Dimona nuclear facility, revealing the existence of a chemical processing plant to extract plutonium from spent reactor fuel.
By 1970 Australia's Joint Intelligence Organisation thought ''Israel could have some weapons''.
Australian policy remains unchanged, with the Abbott government deciding last October not to support a UN General Assembly resolution on nuclear proliferation in the Middle East - 169 countries voted for the resolution. Only five - the US, Israel, Canada, Palau and the Federated States of Micronesia - voted against. Australia abstained.
Former foreign minister Professor Gareth Evans has long been closely engaged with nuclear disarmament issues. Last month he publicly described Israel as one of ''nine nuclear-armed states'' committed to the ''indefinite retention'' of their arsenals.
On Monday Professor Evans declined to explain why Australia had not acknowledged the existence of an Israeli nuclear weapons program, saying only: ''The whole world hasn't acknowledged it. I mean, this is the strange thing, but that's another story for another day.''