BERLIN (AP) — German prosecutors say they have arrested one German man and three German-Iranian dual nationals on suspicion they supplied Iran with parts needed to build a nuclear reactor in violation of the country's trade embargo on such items.

Prosecutors' spokesman Marcus Koehler said suspects Rudolf M., a German, and dual citizens Kianzad Ka., Gholamali Ka. and Hamid Kh., were taken into custody Wednesday on suspicion they had illegally supplied valves needed for the reactor's construction in 2010 and 2011.

The three, whose last names were not released in accordance with German privacy laws, are accused of supplying the parts to Iran through front companies in Turkey and Azerbaijan in deals worth millions of euros.

Some 90 customs agents and prosecutors searched their homes and businesses in Hamburg, Oldenburg and Weimar.