A sum of $11.8 million had been stopped from leaving Switzerland after being frozen between 2007 and 2012, as part of a sanctions programme against Iran to attempt to force the country not to develop and build an atomic bomb.

After decades of negotiation, many United Nations (UN) sanctions were eased in January 2016 after a milestone nuclear deal was reached in 2015, meaning the money could be released, Swissinfo reported.

A spokesperson for the State Secretariat for Economic affairs (Seco) confirmed on Sunday that the money had been unfrozen. It belonged to either individuals, companies or government-owned institutions.

The nuclear deal also opened up Iran to new international business opportunities, some Swiss firms are hoping it could lead to a fresh market outlet.