A post-mortem examination will be conducted on the girl's body in Auckland tomorrow morning.
A number of tests and further scientific analysis may be required to fully understand the cause of death.
Police will continue to work with the family, medical experts and ESR scientists to establish the facts of the situation.
Police are providing support to the family via our support partners, including Victim Support. They said no further comment would be made until after the post-mortem examination.
Incident a 'tragedy'
Neighbours the Herald spoke to said two ambulances, police and a fire truck were outside the Housing New Zealand complex of 12 units yesterday.
One person spoke about returning home from a film early today to find a policeman keeping guard outside the property.
Noel Sanson, a 56-year-old beneficiary who has lived at the block of ageing flats for about six years said the incident was a "bloody tragedy".
He said he saw the young girl's mother in passing and would often say hello.
"She struck me as one of those mothers who was doing their well best to be a good mother," he said.
"From my experience she was a caring mother for her baby to the best of her ability."
He believed the couple who lived at the unit were in their early 20s and were generally quiet apart from an incident some time ago when he said the man living at the house scared the complex's cleaner.
Another neighbour, who asked not to be named, said he felt sorry for the young woman because her partner "often tried to play the tough guy".
"I heard him growling the baby a few times when she was crying," he said.
"He was kind of like 'harden up' or something like that. I felt sorry for her because she seemed a bit immature."
Waikato Senior Sergeant Carl Moon said no further comment would be made until the situation became clearer.
