THIEVES made off with more than £25,000 worth of motorcycles from the British Motocross Grand Prix in Hampshire.
Six bikes were taken during the event at the Matterley Bowl attended by some 25,000 people.
Police believe a gang may have targeted the event to steal the bikes.
Three of the bikes were specialist models worth a combined £21,000. Owned by Husqvarna Motorcycles they were on display at the company’s show truck and tent in the main grand prix paddock.
The alarm was raised when someone on a nearby stand saw three men pushing the bikes through a fence.
Husqvarna spokesman Dave Plummer said: “It’s very disappointing that there was no security around at the time.
“That paddock should have been like Fort Knox. No one should have been able to get anything out of there.”
Between Thursday night and Friday morning a 14- year-old boy, visiting with his family from the Canary Islands, had a £5,500 KTM trial bike stolen.
During the same time period a 49-year-old Dutch man had two motorcycles stolen from the rear of his van.
No arrests have been made.
Sergeant Stuart Gilmore, of North Walls police station in Winchester , believes the thefts could be the work of one gang.
He said: “There is a possibility that all three thefts are linked.”
Husqvarna Motorcycles is offering a reward for information leading to the recovery of its missing bikes.
Contact Dave Plummer on email@example.com or call Crimestoppers on 0800 555 111.
Despite problems away from the track there was a successful weekend of racing on it. History was also made at the event when 339 riders paraded down the track at the same time.