The person who died in a house fire in the South Auckland suburb of Māngere on Saturday was a young child.
A police spokesperson said a scene examination was taking place at the house on Sunday, but there was no information on the cause of the fire at this stage.
Hato Hone St John ambulance said four patients in minor conditions were also assessed at the scene and did not require treatment.
Firefighters were confronted with thick billowing smoke when they arrived at the Tidal Road property on Saturday afternoon.
Fire and Emergency said: "The house was approximately 15m by 10m and was well-involved in fire on our arrival."
Four fire trucks are at the scene and have been able to put the blaze out, she said.
"We have fire investigators responding to ascertain the cause of the fire and police and ambulance are in attendance."
There were two further house fires in Auckland overnight - both in South Auckland's Manurewa.
Both of these fires were deemed suspicious, Fire and Emergency New Zealand said.