"At this stage police are treating the scene as a potential homicide," a police statement says.
"Police are at the address and expect to hold the address overnight while we complete our enquiries to establish cause of death."
Forensic examinations at the house were to be carried out this afternoon.
A woman at Whananaki School, who declined to be named, said she was aware of the police operation.
A resident on Whananaki North Rd said she had seen seven police cars, dog handlers, and a police wagon race down the road.
An employee at Whananaki Holiday Park said she heard there was an incident on Whatmough Rd and a police cordon was in place.
"We just heard that someone's died and someone's injured."
The Fire Service confirmed they were called at 12.40pm to assist police at the incident. Two fire trucks were sent from the Hikurangi station.
Fire Service spokesman Jaron Phillips was unaware of any blaze at the property. The trucks sent out were not specialist hazardous material units.
Whananaki North is a small coastal settlement 48km north-east of Whangarei.
Whananaki North Rd connects to the settlement from State Highway One, just north of Hikurangi, and winds through lush, green countryside and bush for more than 20km before reaching the beach settlement.
The road is sparsely populated, and the house on the property police are focused on is about 100 metres up a driveway, high on the hillside.
