It was a joint operation with the Metropolitan Police. 

The regulator made a similar visit to illegal crypto ATMs in Leeds last month in a joint operation with West Yorkshire Police.

Crypto ATMs allow people to buy or convert money into cryptoassets via a cash machine.

There are currently no legal crypto ATM operators registered with the FCA.

The FCA has previously written to all operators and hosts warning of the legal consequences of failing to register with the FCA.

Mark Steward, executive director of enforcement and market oversight at the FCA, said: “Crypto ATMs operating without FCA registration are illegal and, as today shows, we will take action to stop this. 

“This operation, alongside last month’s action in Leeds, sends a clear message that we will continue to identify and disrupt unregistered crypto businesses in the UK.”

He said that crypto products are not currently regulated and are high risk.

He said: "Cryptoassets are unregulated and high-risk which means people are very unlikely to have any protection if things go wrong." 

The FCA is currently working with the National Economic Crime Centre to plan and coordinate action with law enforcement partners against operators of illegal crypto ATMs.

The FCA carried out the visits using investigative powers under the Money Laundering Regulations 2017. 

The FCA said it will review evidence gathered during the visits and consider taking further action where necessary. 

The FCA publishes a list of businesses that it suspects are operating without its authorisation.