A stunt motorcyclist has been airlifted the hospital with suspected serious injuries after suffering a fall while performing on the Wall of Death.
The incident happened at about 1pm when the rider is thought to have come off his bike during a performance at the Royal Cornwall Show.
The popular attraction sees bikers whizzing round the vertical walls of a cylinder while audiences watch from the top.
The extent of the riders injuries is not known but it is thought they are serious and he was flown to Plymouth's Derriford Hospital by Cornwall Air Ambulance.
A Royal Cornwall Show spokesman said: "An incident has occurred on the Wall of Death attraction at the Royal Cornwall Show this afternoon.
"A man has sustained injuries and has been flown by air ambulance to Derriford hospital for treatment.
"Devon and Cornwall Police have begun an investigation and request that anybody who witnessed the incident please visit the Police pod located at stand 8 near the main entrance."
Sergeant Andy Stewart from Devon and Cornwall Police said: "A man in his forties has received serious injuries as a result of a fall on the Wall of Death, which is a motorcycle display ride.
"He has been airlifted to hospital and police are on the scene investigating how the accident happened. Police are appealing for witnesses - people would have seen the accident happen.
"There is an assumption that the injured man works on the attraction."
