Police are investigating how a 10-month-old baby arrived at Starship Hospital with critical injuries.
However, Detective Inspector Aaron Proctor, Waitemata Police, has confirmed they believe the injuries were "non-accidental" and were now working to find out what happened.
Proctor said the baby was presented to Starship on Wednesday evening with critical injuries.
"Police believe the child's injuries are non-accidental and we are working to establish the circumstances surrounding this."
Officers have been seen at a Vandeleur Ave, Birkdale, property today.
A blue tent has been set up out the front, between the two properties.
Proctor said the child remains in a critical condition in hospital and there have been no arrests at this stage.