Swift was forced to take the unprecedented step of cutting off its financial messaging network to Iranian banks subject to European sanctions back in 2012.

Now, in the nuclear deal reached between Iran and the so-called six world powers, the taps are to be turned back on.

Under the sanctions section of the document, Iran is promised the "supply of specialised financial messaging services, including Swift, for persons and entities set out in Attachment 1 to Annex II, including the Central Bank of Iran and Iranian financial institutions;"

The agreement also allows the transfer of funds between EU and Iranian people and entities, including financial institutions, as well as the opening of Iranian bank branches and subsidiaries in EU states.

In a statement given to Finextra, Swift says: "Swift is aware of the Joint Comprehensive Plan of Action and the potential sanctions relief this may entail.

"For the time being, all the current EU sanctions remain in place, including measures prohibiting companies such as Swift from providing specialised financial messaging services to EU-sanctioned Iranian banks. Swift is incorporated under Belgian law and has to comply with the related EU Regulation, as confirmed by its home country government.

"As a utility with a systemic global character, Swift has no authority to make sanctions decisions. Any decision to lift sanctions on countries or individual entities rests solely with the competent government bodies and applicable legislators."

Iran is the only country to have been cut off by Swift but Europe has floated the possibility of using the messaging network as a tool against other rogue states.

Last year there was a clamour for Russia to be expelled over the crisis in Ukraine, with the European Parliament among those floating the possibility, prompting Swift to put out a statement saying that it "regrets" the political pressure it came under.