"Any death, particularly of a young baby, is a tragedy. I want to assure the Kaitaia community that Northland Police will thoroughly investigate the baby's death," Schmid said.
The scene examination at an address in Kaitaia is still ongoing but is due to be completed later today.
Anyone with information regarding the death of the baby in Kaitaia is asked to contact Kaitaia Police on (09) 408 6500 or call Crimestoppers anonymously on 0800 555 111.
It is the second death of a child due to non-accidental injuries in Northland in six months.
In August last year a 2-year-old died at a property in Mangawhai, resulting in a homicide investigation and charges being laid against a 30-year-old man.
The man, the victim and the child's mother were granted name suppression, along with any information that could identify them.
On average, a child in New Zealand is killed every five weeks, putting the country high on list of world's worst offenders, according to 2016 report.
Sixty-one children died as a result of non-accidental injuries in New Zealand between 2006 and 2016.
A New Zealand Police Homicide Victims Report 2017, released late last year, showed 686 people were killed by homicide in New Zealand over that period, with children under the age of 5 making up 12 per cent of the victims.
