Israel carried out a nuclear explosion in a joint experiment with the Apartheid South African state in 1979, according to a newspaper report.
The Israeli Yediot Aharonot newspaper reported that a newly-disclosed US document contains details of the test which, it says, was carried out on an offshore platform in the northern Atlantic on September 22, 1979.
According to the document, which was released following a request by the Georgetown University in Washington, a US satellite detected the explosion which it says was caused by a nuclear test.
The document was prepared in December 1979 and details a high level of co-operation between Israel and the apartheid state.
Non-proliferation analysts estimate Israel has from 100 to 200 atomic weapons, but the country has not signed the nuclear Non-Proliferation Treaty (NPT) and does not confirm or deny having nuclear weapons.
Israeli's nuclear capability was confirmed in 1986 when Mr Mordechai Vanunu, an employee at its nuclear facility of Dimona, disclosed what was going on there.
He was subsequently kidnapped in Rome by Mossad, the Israeli intelligence service, brought to Israeli and put on trial.