Jeremy Clarkson's "knees turned to jelly" when he realised his friend Richard Hammond had crashed his car while filming for 'The Grand Tour' over the weekend.

Jeremy Clarkson

Jeremy Clarkson

The 57-year-old presenter was convinced his co-star had died after he witnessed the £2 million electric super car he was racing in around a Swiss mountain burst into flames after he careered off a hillside while travelling at 120mph.

Writing for Drivetribe Jeremy explained: "I saw a plume of smoke. Fearful that the 'off' may be quite serious, I urged the driver to get to the top of the hill as quickly as possible. I arrived maybe 30 seconds later and leaped out to see an inferno raging, maybe a quarter of a mile away, at the bottom of a hill.

"And as I stood there, waiting for news, it dawned on me that the burning car was not yellow, as the Aventador was. It was white. Hammond's Rimac had been white. And I can feel it now; the coldness. My knees turning to jelly. It was Hammond who'd crashed. I was joined at this point by James [May]. He was in a right old state, his arms waving frantically, his eyes wide. 'Hammond's in there.' He was screaming."

However, he breathed a huge sigh of relief when he was told that the 47-year-old car fanatic had managed to leap from the vehicle before it erupted into a fireball.

He said: "Then came news from a nearby marshal that he wasn't. That he'd got out before the fire started. And that 'his body' - that's what they said - was behind a screen at the bottom of the hill. I could see the screen. I could see the paramedics behind it. I couldn't see Hammond. I didn't want to see him. Not after a crash that big. He wasn't going to be a pretty sight, that's for sure.

"Our security man is made of sterner stuff and set off down the hill like a racing goat. I watched him arrive at the scene. I watched him intently. I saw him lift his walky talky and I heard him say 'It's all right fellas. He winked at me.' "

Despite the seriousness of the crash, Richard managed to escape with a broken leg.

After he was airlifted to hospital, the journalist - who previously suffered brain injuries and almost died after an accident in 2006, and was involved in a motorbike crash earlier this year - was keen to call his wife Mindy and daughters Izzy, 16, and Willow, 13, to let them know he was OK.