A volunteer marshall was killed after being hit by a car that went off the track during a race at Brands Hatch.
Police and paramedics were sent to the track near Dartford at 3pm on Saturday afternoon, with an air ambulance landing on the circuit.
The crash happened after a car spun off the track during a British Automobile Racing Club (BARC) Car Championship event.
Motorsport UK says it is “deeply saddened” by the accident.
A spokesperson added: “The race meeting was immediately suspended and Motorsport UK, together with the event organiser, has begun a full investigation into the circumstances of the incident.
“The thoughts of everyone at Motorsport UK are with the marshal’s family, the organisers of the event, and other members of the motorsport community who were present.”
BARC said in a statement: “On behalf of everyone connected with the BARC, we are devastated by loss of one of the amazing volunteer marshal community who do so much to enable the sport to take place. Our thoughts and best wishes are with the family and friends of all those involved.