THE secrets of a subterranean factory engaged in the manufacture of Israeli nuclear weapons have been uncovered by The Sunday Times Insight team.

Hidden beneath the Negev desert, the factory has been producing atomic warheads for the past 20 years. Now it has almost certainly begun manufacturing thermo-nuclear weapons, with yields big enough to destroy entire cities.

Information about Israel’s capacity to manufacture the bomb comes from the testimony of Mordechai Vanunu, a 31-year-old Israeli who worked as a nuclear technician for nearly 10 years in Machon 2 – a top-secret, underground bunker built to provide the vital components necessary for weapons production at Dimona, the Israeli nuclear research establishment.

Vanunu’s evidence has surprised nuclear experts who were approached by Insight to verify its accuracy because it shows that Israel does not just have the atom bomb – which has been long suspected – but that it has become a big nuclear power.

Vanunu’s testimony and pictures, which have been scrutinised by nuclear experts on both sides of the Atlantic, show that Israel has developed the sophisticated and highly classified techniques needed to build up a formidable arsenal.

They confirm that Israel now ranks as the world’s sixth most powerful nuclear power after America, the Soviet Union, Britain, France and China – with an arsenal far greater than those other countries, such as India, Pakistan and South Africa, which have also been suspected of developing nuclear weapons.

It has possessed its secret weapons factory for more than two decades, hiding its plutonium extraction processes from spy satellites and independent inspections during the 1960s by burying it beneath an innocuous, little-used building.

The plant is equipped with French plutonium extracting technology, which transformed Dimona from a research establishment to a bomb production facility. Plutonium production rates amount to 40kg a year, enough to build 10 bombs. In the past six years Israel has added further equipment to make components for thermo-nuclear devices.

The 26 megawatt reactor, also built by the French, has been expanded and is probably now operating at 150 megawatts to allow it to extract more plutonium. An ingenious cooling system disguises the output.

The nuclear scientists consulted by The Sunday Times calculate that at least 100 and as many as 200 nuclear weapons of varying destructive power have been assembled – 10 times the previously estimated strength of Israel’s nuclear arsenal.

The scientists include Theodore Taylor, who was taught by Robert Oppenheimer, the father of the atomic bomb, and worked on America’s first bomb designs. He later went on to head the Pentagon’s atomic weapons test programme.

Taylor studied the photographs taken by Vanunu inside Dimona and a transcript of his evidence near Washington last week. He said: “There should no longer be any doubt that Israel is, and for at least a decade has been, a fully-fledged nuclear weapons state. The Israeli nuclear weapons programme is considerably more advanced than indicated by any previous report or conjectures of which I am aware.”

Vanunu says that despite tight security he was able to smuggle a camera into Machon 2 and take more than 60 photographs.

The assessments of Taylor have been confirmed by other top nuclear scientists who were shown the pictures and detailed evidence.

Israel refused to comment on the evidence but confirmed that Vanunu worked for the Israel Atomic Energy Commission in Dimona. He was made redundant last November with 180 other Dimona workers during a cost-cutting drive.

Security men had grown concerned about Vanunu’s political contacts with West Bank Arab students during a part-time philosophy course that he was taking at Beersheba University.

Before publication Vanunu, now 63, was lured into flying to Italy for a holiday by a Mossad agent named Cheryl Bentov. He was captured by Israeli agents, smuggled to Israel and put on trial on charges of treason and espionage. He was released in 2004 but is not allowed to leave the country and is subject to numerous other restrictions including a ban on speaking to foreign journalists.

Times Recommends

• Fish and chip shops ‘selling cobbler as cod’
• T in the Park festival at Kinross
• Body Watch