Spanish police say they have arrested four people who allegedly planned to send industrial machinery that could be used to make missiles to Iran.
A Civil Guard statement on Monday said officers seized two Leifeld metalworking machines that had been imported illegally from Britain last year.
The statement said the machines were classified as "dual use" - meaning they could be used in both civilian and military industry - and their shipping to Iran would violate UN sanctions.
It said three Spaniards and one Iranian were arrested in the cities of Barcelona, Tarragona and Palma de Mallorca.
They were charged with being members of a criminal gang, trafficking dual-use goods and money laundering.
The statement said police also confiscated 10,000 euros ($13,700) and documents on exporting dual-use technology.
In January, the European Union and the United States suspended a range of sanctions against Iran after Tehran began implementing a deal to curb its nuclear programme.
The West alleges that Iran is covertly using its nuclear programme to build a nuclear bomb. Tehran insists the programme is solely for peaceful purposes.
Under the Geneva deal reached in November of 2013, Iran agreed to halt its 20 percent enrichment programme but to continue enrichment up to 5 percent.
It also agreed to convert half of its stockpile of 20 percent enriched uranium to oxide and dilute the remaining half to 5 percent over a period of six months.
In addition to the enrichment measures, the six-month interim deal also commits Iran to opening its nuclear programme to greater UN inspections and providing more details on its nuclear activities and facilities.