The Times newspaper claims to have obtained ''confidential intelligence documents'' showing that Iran is testing a final component to build a nuclear bomb.

Iran is set to launch its first civilian nuclear power plant in the next few months, but denies that its controversial atomic energy program has military aims.

The British paper said the Iranian documents "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."

The paper said independent experts have confirmed that the neutron source mentioned in the documents, uranium deuteride, has no possible use other than in a nuclear warhead.

The Times said the documents have been seen by British intelligence and passed on to the International Atomic Energy Agency (IAEA).