Steve Mnuchin claimed cryptocurrency had made the Treasury make proposals of converting the US currency into a "digital dollar".

While he said those plans were not viable in the near future, Mr Mnuchin revealed that the Government had several fears over the currency boom.

He said his major concern was making sure "bad people cannot use these currencies to do bad things".

The Treasury Secretary told the Economic Club of Washington: "I want to be sure consumers trading this understand the risks.

"I'm concerned consumers could get hurt."

Mr Mnuchin said an urgent G20 summit on cryptocurrencies was needed to prevent bitcoin from being used like "Swiss numbered bank accounts". 

He said the US was investigating how to "track activities" for bitcoin.

Several governments around the world have already banned initial coin offerings and are looking at strict regulation to bring cryptocurrencies under the control of the global financial system.   

This crackdown on the digital currencies is largely due to the decentralised anonymity that surrounds cryptocurrency.

Despite this, ripple has recently moved to work with banking systems to reduce transfer costs.