A track marshal has died in a motorbike accident at the Oulton Park race circuit in Cheshire.
The man, who is 49 and from Davyhulme in Greater Manchester, was killed when a rider lost control on a corner of the track and came off his Yamaha 600.
It is believed his bike hit the marshal causing fatal injuries. The rider escaped uninjured.
The accident happened during a test day organised by the Motorcycle Circuit Racing Control Board (MCRCB).
MotorSport Vision Chief Executive Jonathan Palmer said: "This was an extremely tragic accident and we are desperately sorry that someone should lose their life serving the sport they loved.
"We extend our deepest sympathies to the marshal's family and friends.
"The precise circumstances are being fully investigated, but it appears that this was a freak accident that happened when the marshal was at his flag marshal post."
Cheshire Police are investigating.
MotorSport Vision's website describes the track as "one of the most technically challenging tests for any driver who takes on its undulating twists and turns."