Germany accuses four of breaking Iran nuclear embargo
Four men have been arrested in Germany on suspicion of illegally supplying Iran with parts needed to build a nuclear reactor.
The suspects were held following searches of homes and business in Hamburg, Oldenburg and Weimar.
They are accused of using front companies in Turkey and Azerbaijan to supply the parts in deals worth millions of euros.
Germany has an embargo on nuclear-related trade with Iran.
Many Western countries have concerns about Iran's nuclear programme, but Iran insists it is for peaceful purposes.
Tehran is currently building a heavy-water reactor near the central town of Arak.
A US think-tank has said Iran aims to have the reactor up and running next year, but the start date could be delayed by an inability to get the right specialist parts.
'Stop, shut and ship'
German prosecutors said the arrested men - one German citizen and three Iranian-German dual nationals, were supplying special valves to be used in heavy water reactors.
They are accused of breaking the arms embargo, as well as export restrictions on goods that could be used for military purposes.
Prosecutors say the men, known as Rudolf M, Kianzad Ka, Gholamali Ka, and Hamid Kh, knew what the parts would be used for.
Germany privacy laws prevent their full names being released.
A fifth suspect has not been named.
Some 90 customs officials and prosecutors were involved in the searches that led to the arrests.
The suspects are expected to appear in court later on Wednesday.
The United Nations, the United States and the European Union have a wide range of sanctions in place aimed at putting pressure on Iran to make concessions on its nuclear programme.
In July, US President Barack Obama ordered new economic sanctions against Iran's energy sector and some financial firms to make it harder for Tehran to evade the existing sanctions.
The latest round of talks between six world powers - the US, China, Russia, France, the UK and Germany - and Iran on Tehran's controversial programme ended without a breakthrough in Moscow earlier this year.
The world powers are demanding that Iran suspend enrichment of uranium to 20%, close down an underground enrichment facility near the city of Qom and export its stockpile of 20%-enriched uranium - measures described by one Western diplomat as "stop, shut and ship".
In return, the world powers say they are prepared to start by offering help with nuclear safety measures.
But Iran wants the West to lift sanctions. It says its "non-negotiable" right to enrich uranium must be recognised.