Newly published research has added more weight to the worst-kept secret in Israel, that the country has an illegal nuclear arsenal and that it conducted a covert nuclear test 39 years ago.
The article published in the Science & Global Security journal in May revealed that radioactive isotopes were found in Australian sheep following a suspected Israeli nuclear test in the Atlantic Ocean in 1979.
In September 1979, the U.S. "Vela" satellite detected a mysterious double flash near a remote island group off the coast of South Africa.
Analysts have long suspected the incident was an illegal nuclear weapons test carried out by Israel in cooperation with the former Apartheid regime.
"New analysis of radionuclide and hydroacoustic data supports a low-yield nuclear weapon test as a plausible explanation for the still contentious Vela Incident," the study says.
"This article concludes that iodine-131 found in the thyroids of some Australian sheep would be consistent with them having grazed in the path of a potential radioactive fallout plume from a low-yield nuclear test," it added.
The researchers said their data came from several declassified letters and reports.
Israel has never confirmed nor denied the existence of a nuclear programme and dismissed allegations it was responsible for the 1979 incident.
Despite the secrecy surrounding Israel's nuclear arsenal, a private email leaked by former U.S. Secretary of State Colin Powell alluded to Israel having an arsenal of "200 nuclear weapons".
Over recent decades Israeli officials have occasionally let slip the intention and rationale behind its opaque nuclear weapons programme.
In 1986, Israeli nuclear whistleblower Mordechai Vanunu was jailed for disclosing the inner workings of Israel's Dimona nuclear plant.
The former nuclear technician spent more than 10 years of his sentence in solitary confinement.
This article has been adapted from its original source.
