The Treasury has set out guidance on how to protect against illicit financial transfers involving Iran.

The US government is advising financial bodies such as banks, money services' businesses and dealers, among others, on how to detect “potentially illicit” transactions linked to Iran more effectively.

With the US administration taking a hard line on a country that it has accused of trying to develop nuclear weapons in spite of assurances to the contrary, it is hunting down financial transactions affecting the US financial system. In recent years a number of major banking groups, such as BNP Paribas, have fallen foul of sanctions affecting Iran, among other nations.

The US Treasury issued a 19-page note called “Advisory on the Iran Regime’s Illicit and Malign Activities and Attempts to Exploit the Financial System”.

“The Iranian regime has long used front and shell companies to exploit financial systems around the world to generate revenues and transfer funds in support of malign conduct, which includes support to terrorist groups, ballistic missile development, human rights abuses, support for the Syrian regime, and other destabilizing actions targeted by US sanctions,” the note said.

After a deal agreed under the previous Barack Obama administration, the current government has re-imposed sanctions on the country.