Hundreds of drivers may have been duped into driving too fast on a dual carriageway in South London, after a 50mph sign put up there.

LBC reports up to 500 people are complaining about being ticketed on the A20 near Sidcup on a stretch of the road where the speed limit had been temporarily dropped to 40.

It appears a 50mph sign was installed by an “unauthorised third party” after speed cameras were set to match the lowered limit.

Dominic Smith, director at Patterson Law, the biggest national firm specialising in motoring offences, told the radio station never seen a response like it.

Speaking to LBC’s Nick Ferrari at Breakfast, he said: “I haven’t ever seen anything quite like this, on this magnitude.

“We’ve been contacted in the last week by about 400 or 500 individuals, of which about 100 to 150 are at risk of losing their licenses because of this.

“Usually when a new speed camera goes up, we can tell here because we get maybe about two or three enquiries a day for a couple of days – 40 to 50 a day we’re getting at the moment. I’ve never seen anything like it.”

Police told LBC an investigation has been launched into the incident as an attempt to “pervert the court of justice”.

(File Picture – Yay Images)