Richard Hammond in horror crash in Swiss mountains

FORMER Top Gear star Richard Hammond has survived a horrific car accident in the Swiss mountains.

Hammond, 47, was filming his Amazon TV show The Grand Tour when his electric supercar left a mountain road in St Gallen in northeastern Switzerland and burst into flames.

He was airlifted to hospital but tests showed he had escaped the high-speed crash and ensuing fireball with a fractured knee.

Hammond was lucky to escape the crash. Freuds via AP

Co-star and another former Top Gear presenter, Jeremy Clarkson, tweeted about the accident, saying: "It was the biggest crash I have ever seen and the most frightening but incredibly and thankfully, Richard seems to be mostly okay.''

Photographs showed a burned-out wreck of a car resting on its roof.

James May, Richard Hammond and Jeremy Clarkson used to host Top Gear. Supplied

Hammond was critically injured in a high-speed crash back in 2006 which left him in a coma for several weeks but recovered and went on to build an international following with Top Gear before following Clarkson when he was sacked from the show in 2015.

The accident is thought to have happened on Saturday afternoon.Richard Hammond was very lucky not to die in this smash. Picture: AP

This photo issued by Freuds shows the car that was involved in a crash where Richard Hammond escaped serious injury, in Switzerland, Saturday June 10, 2017. Freuds via AP

St Gallen police spokesman Gian Andrea Rezzoli told Swiss newspaper 20 Minuten that the driver of the car was taken by air ambulance to hospital and the fire was extinguished by firefighters.

Hammond was conscious and got himself out of the car before it was engulfed in flames.

The Grand Tour confirmed Hammond was completing the Hemburg Hill Climb in Switzerland in a Romac Concept One, an electric supercar built in Croatia, when the accident happened.

"Richard was conscious and talking and climbed out of the vehicle himself before it burst into flames,'' the show said in a statement.

"No-one else was in the car …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.''