MILAN (Reuters) – The spread of cryptocurrencies without any clear regulation is cause for concern and could harm the functioning of the market, the head of Italy’s stock market regulator said on Monday.

Paolo Savona joined a host of institutional leaders who have called for more regulation and said cryptocurrencies could facilitate illegal activities such as money laundering and even undermine the ability of central banks to conduct monetary policy.

“Without proper oversight, there could be a deterioration of market transparency, the basis of legality and rational choice of (market) operators,” said the president of Consob during the presentation of the annual report of the watch dog.

Europe and the United States both work to regulate digital assets and their providers, as investors seek new ground rules.

Along with the changing regulatory framework, some countries, including China, Britain and Russia, are considering launching their own central bank digital currencies.

Savona said there are between 4,000 and 5,000 cryptocurrencies in circulation without any form of actual regulation.

“If we add to this Consob’s recent experience in Italy shutting down hundreds of websites illegally collecting savings, the picture that emerges is worrying,” said Savona.

He warned that currencies could act as a shield for criminal activities such as tax evasion, money laundering, terrorist financing and kidnappings.

“If it takes too long at European level to find a solution, (Italy) will have to take its own measures,” he said.