If the difference is too great, the system flags a caution. The tool also checks the vehicle’s main details and can show previous advertisement listings, including the vehicle’s price and mileage and seller’s name. Hunt said: “These sophisticated scams are causing unsuspecting individuals to lose substantial amounts of money and are getting smarter. 

“However, while Advert Check serves as a robust tool for scam detection, it doesn’t provide an absolute guarantee and users should still exercise due diligence when making a purchase.”

How effective is Brego Advert Check?

Within seconds of logging onto Facebook Marketplace, we found our first suspicious car, listed on the site’s home page. The 2012-reg Range Rover Evoque 2.2 SD4 automatic had 53,000 miles on the clock and was being advertised for £4750. 

According to Advert Check, this was £6141 less than the estimated dealer price and £4616 less than the auction value. We messaged the seller for more details but when, a few minutes later, we rechecked the listing, it had been withdrawn. 

Drilling deeper into Facebook Marketplace, we then found a suspiciously cheap Range Rover Velar. Registered in 2017 and with 100,000 miles, it was listed at just £10,900, which is £12,349 less than Advert Check’s estimated dealer price and £9094 less than the auction value.