"We are working closely with partners in government and law enforcement both here and abroad, including regulatory authorities, to share intelligence and act to prevent sanctions evasion, including through cryptoassets," the financial regulators said.

"We also remain ready to act in the event of sanctions breaches," added the statement from the Office of Financial Sanctions Implementation, the Financial Conduct Authority (FCA) and the Bank of England.

The statement said the use of cryptoassets to circumvent economic sanctions was a criminal offence, and that sanctions regulations did not differentiate between cryptoassets and other forms of assets.

The FCA had already written to all registered cryptoasset firms and those holding temporary registration status to highlight those entities and individuals who had been sanctioned, it added.

"Both the FCA and the Prudential Regulation Authority will act if they see authorised financial institutions supporting cryptoasset firms operating in the UK illegally," the statement said.

A senior European Union official said last week that the European Commission is studying whether cryptoassets are being used to get round financial sanctions imposed on Russian banks.