The smoking gun. "Secret document exposes Iran's nuclear trigger," by Catherine Philp in The Times, December 14 (thanks to Kris):

Confidential intelligence documents obtained by The Times show that Iran is working on testing a key final component of a nuclear bomb.

The notes, from Iran's most sensitive military nuclear project, describe a four-year plan to test a neutron initiator, the component of a nuclear bomb that triggers an explosion. Foreign intelligence agencies date them to early 2007, four years after Iran was thought to have suspended its weapons programme.

An Asian intelligence source last week confirmed to The Times that his country also believed that weapons work was being carried out as recently as 2007 -- specifically, work on a neutron initiator.

The technical document describes the use of a neutron source, uranium deuteride, which independent experts confirm has no possible civilian or military use other than in a nuclear weapon. Uranium deuteride is the material used in Pakistan's bomb, from where Iran obtained its blueprint.

"Although Iran might claim that this work is for civil purposes, there is no civil application," said David Albright, a physicist and president of the Institute for Science and International Security in Washington, which has analysed hundreds of pages of documents related to the Iranian programme. "This is a very strong indicator of weapons work."

The documents have been seen by intelligence agencies from several Western countries, including Britain. A senior source at the International Atomic Energy Agency (IAEA) confirmed that they had been passed to the UN's nuclear watchdog.

A Foreign and Commonwealth Office spokeswoman said yesterday: "We do not comment on intelligence, but our concerns about Iran's nuclear programme are clear. Obviously this document, if authentic, raises serious questions about Iran's intentions."

Responding to The Times' findings, an Israeli government spokesperson said: "Israel is increasingly concerned about the state of the Iranian nuclear programme and the real intentions that may lie behind it."...

Mr Fitzpatrick said: "Is this the smoking gun? That's the question people should be asking. It looks like the smoking gun. This is smoking uranium."