Crooks are posing as solicitors to scam millions of pounds out of homebuyers in a so-called Friday afternoon fraud.
The Law Society of England and Wales said that the scams were on the rise amid a boom in the property market.
The criminals hack into e-mails between solicitors and their clients and then, as the money is about to be moved, impersonate the lawyer and ask the homebuyer to pay the house deposit or balance into an account they control.