Police arrived at South Auckland property to discover a dead body and a second person critically injured.
Officers arrived at the house in McNally Rd in Pukekohe at 9am this morning and found a man with critical injuries.
"Subsequently, while making inquiries at the scene police have located another person deceased at the address.
"We are now working to formally identify the person and notify their next of kin."
The death is currently being treated as "unexplained". An autopsy will take place tomorrow.
The injured man was taken to Middlemore Hospital and is in a critical condition this afternoon, police said.
A scene examination is under way this afternoon at the McNally Rd property and a scene guard will remain in place overnight.
A St John spokeswoman said one ambulance, one rapid response unit and one incident manager was sent to the scene.
St John was alerted to the Pukekohe incident at 9.06am.
- Police ask that anyone who may have information that may assist their inquiries to contact Counties Manukau Crime Squad on 09 261 1321.