That means an estimated 20.3 million homeowners and renters — 97.5 percent of homeowners — are still at risk.

Olly Thornton-Berry of Sordfort said: “Fraud is a huge problem in the UK property market. We have seen some alarming cases where fraudsters have obtained ownership of properties using fake documents to impersonate registered owners. Vacant properties, rental properties and those without a mortgage are particularly at risk.

In November last year, a man returned from work in Wales to find that someone had broken into his home in Luton, changed the keys and started renovations. A BBC investigation revealed that his identity was stolen to sell the house and the fraudster took the proceeds.

Thirdfort urges homeowners to sign up to the Land Registry’s title alert service, which sends email notifications when activity searches and applications are made using a tracked address.

Users do not need to own the property to set up alerts. The same property can be controlled by different people.