The front of the Rotorua Aquatic Centre has been badly damaged.
A police spokeswoman said police were called to the scene about 5.45am and it appeared the building had been hit by a car some time overnight.
She said the car was not at the scene and inquiries were being made in relation to any potential CCTV footage that might be available.
A worker at the centre said they had no idea what had happened or when exactly, but suspected it may have been caused by a car hitting the doors in the early hours of this morning.
She said they reported it to police and officers had been down to the scene to investigate.
Local swimmer Maxine Parker, who came across the damage, said she had seen one small tyre mark and thought it looked like it had been "rammed like they do to liquor stores".
She said as it was a council facility, it would likely be "our rates that pay for insurance and its excess".