The president of the Foxton Racing Club is baffled as to why anyone would want to destroy their racecourse, which has been set alight three times in the past five days.
The first fire was on Friday, when the grandstand and the race day office were badly damaged in a late-night blaze.
The following night, at about 10.50pm, firefighters responded to calls of a second fire, this time in one of the stable blocks, but it was too late and the structure was destroyed.
Last night firefighters spent about three hours battling a blaze in another stable block, which was severely damaged.
Police are treating all three fires as suspicious and officers from Foxton and Levin have launched a full investigation.