A car has plunged into the Waipoua River in Masterton and police are seeking the owner to establish whether anyone was inside the vehicle and may have been swept downstream.
At this stage it is "too dangerous" to enter the river to check if there are any occupants.
While initial responders said it did not appear anyone was inside, police have not ruled out someone escaping and the car as it went into the river and not making it out of the water.
Police received a report of a car in the river at Opaki Road, Masterton, about 7.15am.
Since then the vehicle has been swept downstream.