Police have used a thermal camera to locate a fleeing driver hiding out in the Waikato River.
They say officers were searching for a vehicle in Hamilton shortly before midnight on Monday, and found it upside down in an area flooded by the river's overflow, with two injured occupants nearby.
They say a 19-year-old woman was found lying face up in the water and a 41-year-old man was discovered underneath her.
Police say they borrowed a thermal camera from firefighters and found a third person in the river, clinging to the bank, about two hours after taking off from the crash scene.
The 29-year-old man has been taken to hospital for treatment for hypothermia.