Police in South Auckland say they plan to speak further with the teenage parents of a critically ill baby.
A four-month-old boy was taken by ambulance from Papakura to Middlemore Hospital on Saturday night with what the police describe as non-accidental head injuries. He was later transferred to Starship Hospital.
Police say they hope the boy's parents, who are 18 and 19 years old, will expand on their initial statements.
Child Youth and Family has become involved with the baby's 18 month old brother.
Neighbours say the couple often became embroiled in domestic disputes.
Police say the speculation about what happened to the baby is unhelpful.