It used to be easy for investors to turn up at an auction unprepared and buy a property without having to demonstrate that their money came from a legitimate source.

“You could walk in from the back of the room, a complete stranger; you were reading the catalogue for the first time; you had done no homework; you just put your hand up,” says Gary Murphy, partner and auctioneer at Allsop Residential. “We’ve sold multimillion-pound properties this way.”

Today, it is much harder for investors to buy property on a whim like this. Since the introduction of the Fourth Anti-Money Laundering and Terrorist Financial Directive in June last year, the rules have become much stricter. Investors have to be ready to face due diligence and anti-money laundering (AML) checks on the day of the auction.

Almost a year after the regulations came into force, property auction houses have all adapted their policies but significant differences remain between firms as to their interpretation of the rules.