Drone filming spotted at Southwell racecourse
Racecourse owners say they regard drones apparently broadcasting live pictures of meetings as theft.
Venues across the UK have seen an increase in unauthorised drones being flown nearby.
Drone footage can be two seconds ahead of broadcasters, giving some punters a financial edge while "live betting".
A BBC team filmed a drone flying over Southwell Racecourse, whose owners said this had happened regularly for six months.
Despite potential impact on the value of official coverage and hospitality viewing, flying the drones from public land means they are not breaking the law.