Foxton Racecourse has been struck by another arson attack, the fourth fire in 10 days.
A security guard spotted the fire at the caretaker's shed early yesterday morning.
He raised the alarm and with the assistance of the caretaker used fire extinguishers to put out the flames.
There was some damage to the wooden door of the shed.
Police say this has become a serious issue, and it's pure luck that no one has been seriously injured or killed.