Officers visited 50 estate agents across England suspected of trading without being registered, which is required under UK money laundering laws.

Those targeted included 35 estates agents in London, five in Leicester, four in South Bucks and Berkshire, three in Greater Manchester and one each in Watford, Wakefield, and Wolverhampton.

The tax regulator said it is the first week of action involving intelligence-led, coordinated activity aimed at estate agents trading without registering with HMRC -- a requirement for tracking the global inflows into UK property.

The rumble coincides with the agency's decision to name and shame businesses failing to comply with regulations. Between June and October 2018, nine UK companies have been listed and penalised for non-compliance on the government website. Estate agent Countrywide leads in penalties, fined £215,000, followed by Tepilo fined £68,595, but a number of tax and accounting firms also fell foul of reporting rules. None of the nine listed is appealing fines.

“The vast majority of estate agents play by the rules and help us to crack down on dirty money. But I have zero tolerance for firms prepared to turn a blind eye to the law. Money laundering regulation exists to help protect honest business, so anyone who flouts the law should know that swift action will be taken,” said John Glen, economic secretary to the Treasury.

Crime agencies see estate agents as a critical defence against money launderers, which is “why they’re under a legal – and moral – obligation to file a report when they spot something amiss,” said Ben Wallace, mnister for national security and economic crime.

Wallace added: “It’s wrong to think of money laundering as a victimless crime. Those with dirty cash to clean don’t just sit on it – they reinvest it in serious organised crime, from drug importation to child sexual exploitation, human trafficking and even terrorism.”

A recent report by the global Financial Action Task Force, founded 20 years ago to get countries cooperating more on AML enforcement, shows the UK scoring high in tackling the problem, with HMRC part of that effort.

The agency has reported carrying out more than 5,000 interventions on businesses the last three years, and issued 655 penalties worth £2.3 million between 2017 and 2018. It has also recovered more than £31 million under the Proceeds of Crime Act, the UK’s principle money laundering legislation.

“Estate agents need to understand that criminals prey on weaknesses, so it’s vital they take all steps to protect themselves. The money laundering regulations are key to that, but there’s still a minority of agents who ignore their legal obligations. These inspections are a wake-up call that if you continue to trade illegally we will come knocking,” said Simon York, director of HMRC’s Fraud Investigation Service.