A fire at a police station in the Bay of Plenty sparked two callouts.

Firefighters were initially called to the blaze in Taneatua at 10.45pm, but had to return this morning because there was a flare up.

Fire and Emergency New Zealand northern communications shift manager Daniel Nicholson says they are unable to determine where the initial fire started.

'When we arrived, it (the building) was fully involved with fire. The building size was 3m by 9m.

'We had the investigators respond to the station and the fire investigator is currently at the scene.

'I don't believe it is being treated as suspicious.”

Daniel says crews left the police station at around 2am, with some crews going back this morning because there was a flare up.

'We went back there and just dampened it down.”