Senior Sergeant Craig Dinnissen, of Dunedin, said a staff member was having dinner at the central city police station late on Saturday when they heard an "almighty ruckus downstairs'' and went to investigate.
They saw a man slamming the statue, which sits atop a tall plinth in the foyer, onto the floor.
"He was duly arrested and processed for wilful damage,'' Snr Sgt Dinnissen said.
There was no word on the 42-year-old's motivation for the alleged attack.
It depicts a mermaid atop a seashell, as a rabbit (or hare) looks on.