The National Council of Resistance of Iran (NCRI), which is listed as a terrorist organisation by the U.S. State Department but has provided accurate information on secret Iranian nuclear activities, said Iran obtained beryllium from China in 2004.
"The (Iranian) Ministry of Defence is vigorously trying to obtain beryllium. This includes smuggling 20 kg (44 pounds) of beryllium from China in 2004 for use in the regime’s nuclear weapons project," the NCRI said in a statement.
Iran denies U.S. accusations that it is developing nuclear weapons under the cover of its civilian nuclear programme. It says its atomic ambitions are limited to the peaceful generation of electricity.
Beryllium has many innocent uses such as in spark plugs and X-ray equipment but it can also be combined with polonium-210, a substance Iran is known to have worked with, to initiate the chain reaction in a nuclear bomb. It is under internationally agreed export controls.
The NCRI has made numerous accusations in recent months about what it says is Tehran’s secret nuclear weapons programme.
The NCRI said in February Iran had tested a trigger mechanism using beryllium and polonium-210, and was close to producing such "neutron initiators" on an industrial scale.
Diplomats have said there is evidence to suggest that Iran tried to buy significant quantities of beryllium metal and that the IAEA was aware of at least some of the attempts.
The IAEA has been investigating Iran’s nuclear programme for almost three years. It has found no hard evidence that Tehran is developing nuclear weapons but is not convinced Iran’s atomic ambitions are peaceful.
The IAEA’s investigation began after the NCRI revealed the existence of a massive underground uranium enrichment site at Natanz and a heavy water production facility at Arak.