Dramatic video shows moment former Top Gear presenter Richard Hammond crashes sports car, slides off hillside and explodes into flames

Dramatic footage shows the moment ex-Top Gear star Richard Hammond's car crashed as it veered off a hillside and exploded into flames.

A witness was capturing video as Hammond, 47, went around a curve in the mountain road as he participated in the Bergrennen Hemberg race.

The Sh100 million Rimac Concept One electric super car then went off the road and slid down the hillside, where it later caught fire.

Hammond, who was filming scenes for The Grand Tour, escaped serious injury and was airlifted to hospital after climbing out of the car on his own, a spokesperson said.

The spokesperson said: "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."

The cause of the crash is being investigated, the spokesperson added.

The person who captured the video claimed the car caught fire due to the batteries in the vehicle.

Photos showed a wrecked car in flames alongside a road in the canton of St. Gallen before the blaze was extinguished by firefighters.

The Rimac Concept One has a top speed of about 350km/hr and can go from 0-100 km/h in just 2.5 seconds.

Hammond is not believed to have been seriously hurt

It was not known how fast Hammond was travelling when the car veered off the road.

It is the second time Richard Hammond has been seriously injured in a car, the first being in September 2006 when he crashed a Vampire dragster while travelling at 288mph.

Hammond was in Switzerland filming scenes for the Amazon series The Grand Tour, along with ex-Top Gear co-hosts Jeremy Clarkson and James May.