Top Gear presenter Richard Hammond has been injured in an accident while filming an edition of the programme, the BBC said.
Hammond, who often drives high-performance cars as part of presenting the show, has been taken to hospital following the incident at an airfield near York.
A BBC spokeswoman said: "The incident happened quite recently and the focus of our attention is on Richard at this stage. "We will make further details known as soon as they are available."
Inspector Mike Thompson, of North Yorkshire Police, said officers were dealing with the incident at the airfield north-east of York.
He said: "At 5.45pm (on Wednesday) evening we received a report via the fire service of a male person trapped in what was described as an overturned jet car which had been driven on the airfield.
"The male occupant has received serious injuries and has been airlifted to hospital at Leeds." He said no further details were available at this time.
Hammond was in a "critical" condition at Leeds General Infirmary, a hospital spokesman said.
A North Yorkshire Police spokesman confirmed the accident happened on Elvington airfield, which is seven miles to the south-east of the city.
He said the presenter was filming an episode of Top Gear at the airfield at the time.
The spokesman added: "Relatives have been informed and are en route to the hospital itself."