A 22-year-old woman has been granted name suppression after being charged with murder over the death of a four-week-old baby in January last year.
The boy was taken to Starship Hospital with head injuries, and died on 16 January, 2022.
Detective Inspector Scott Beard said police had been conducting inquiries since being contacted by medical authorities after the death.
The woman has been charged with murder, ill-treatment of a child and three counts of assaulting a minor.
Auckland District Court Judge Belinda Sellars remanded the woman in custody until her next court appearance in February.
"Any baby homicide is a difficult investigation and the police team have worked hard to get to this stage," Beard said.
"This is a sad and tragic case for all those involved, but it is important those allegedly responsible for the abuse of children are held to account."