Two people have been arrested by Spanish Police under suspicion of delivering materials destined for use in Iran’s nuclear program.

Authorities stopped a truck in northern Spain that turned out to be carrying corrosion-resistant valves, said Reuters, quoting a statement by the Spanish interior ministry.

The two men reportedly worked for Fluval Company, and by examining company documents, the Spanish authorities discovered that Fluval was using fake companies “in the United Arab Emirates for the deliveries, channeling cash through banks in other countries.”

The ministry added that it found links between Fluval and Iranian firms that are on the EU blacklist of companies connected with Iran’s nuclear program.

The European Union has ratcheted up sanctions on Iran over their nuclear disputes. While Iran insists that its nuclear program in peaceful, the EU and the Unites States echo Israel’s concern that Iran’s nuclear activities may be a ruse for developing nuclear weapons.

Negotiations over the nuclear disputes between Iran and the world powers are to continue this month.