Richard Hammond has been involved in a crash while filming, leaving him knocked out.
The Grand Tour presenter was filming in a remote part of Africa when he came off a motorbike and hit his head, leaving him unconscious.
Jeremy Clarkson told The Sun: "He really did hurt himself quite badly."
A source added: "Richard was travelling quite fast when he came off. It caused instant horror on set.
"There was a lot of concern. If his injuries had been serious it wouldn't have been easy to get medical attention.
"It's very remote there and facilities are basic.
"The lads are known for having a laugh on set but Richard's previous accident is fresh in their minds. They were all shaken by the latest incident.
"But now they know Richard is fine they are back to jokes and banter."
It is believed that the crash will be featured in series two of The Grand Tour.
Eleven years ago, Hammond almost died while filming an episode of Top Gear. He was travelling at 288mph in a jet-fuelled car when a tyre blew and he lost control of the vehicle, leaving him in a coma for two weeks.
He later revealed that he suffered depression, memory loss and paranoia after the crash.
Featured Image Credit: PA/Top Gear