Richard Hammond's car veers off hillside before it burst into flames in 'most frightening' crash Jeremy Clarkson has ever seen

Former Top Gear host Richard Hammond has escaped serious injury after a crash in Switzerland.

Mr Hammond was attending a car race when his vehicle, a Rimac electric supercar believed to be worth £2 million, left the road and mounted a grassy verge.

"It was the biggest crash I've ever seen and the most frightening ," Jeremy Clarkson tweeted on Saturday afternoon. "But incredibly, and thankfully, Richard seems to be mostly OK."

The Grand Tour tweeted: "Richard Hammond was involved in a serious crash after completing the Hemburg Hill Climb in Switzerland in a Rimac Concept One, an electric super car built in Croatia, during filming for The Grand Tour Season 2 on Amazon Prime, but very fortunately suffered no serious injury.

"Richard was conscious and talking, and climbed out of the car himself before the vehicle burst into flames.

"He was flown by Air Ambulance to hospital in St Gallen to be checked over revealing a fracture to his knee.

"Nobody else was in the car or involved in the accident, and we'd like to thank the paramedics on site for their swift response.

"The cause of the crash is unknown and is being investigated."

Swiss police directed calls to organisers of the Bergrennen Hemberg, an annual mountain race held in the area of Hemberg.

Images on the race's official Instagram showed vehicles drifting rally-style around a tarmac track.

It's not the first time Mr Hammond has been involved in a serious accident while filming.

The father-of-two was in a coma for two weeks in 2006 after a jet-powered car he was piloting for Top Gear crashed.

The presenter later revealed he suffered depression, paranoia and memory loss due to brain damage caused by the crash in York.

Three months ago he was knocked unconscious after falling off a motorbike in Mozambique.

A source told The Sun after his latest crash: “Richard is conscious but very shaken.

“He is currently being treated in hospital for a fractured knee and having the once over. It’s quite incredible he’s come away from this with nothing more serious quite frankly.

“The crash was really bad. The car completely flipped and then burst into flames.

"There was real concern for Richard but the emergency services were quickly on hand and he’s a very lucky boy.

"It brought back horrendous memories of the 2006 crash for those who witnessed it."