Ms Perks said his patrol car was parked behind a fence, out of sight from where the officer was dealing with the group.
"While the officer was running checks on the vehicle in the reserve, his patrol car was being vandalised," she said.
"He returned to his vehicle to find it damaged. It's not clear if the same group did it."
She said the car's back window and rear tail lights were smashed and the side mirrors had been hit as well.
The vandalism was estimated to cost $1000 to repair.
Ms Perks said police would like to hear from members of the public who saw what happened.
Information can be passed on by calling (07) 348 0099 or anonymously by calling 0800 555 111.