The Office of the Chief Social Worker is to review Child, Youth and Family's involvement in the case of an Auckland baby who died after suffering serious head injuries.
Cezar Taylor, who was six months old, died on Wednesday night in Starship Hospital.
Police have said his injuries were consistent with shaking and blunt-force trauma.
The partner of the baby's mother, James Allan Hemana, was arrested on Wednesday and charged with assaulting a child. He will appear in Manukau District Court on Friday.
Police are considering laying further charges.
Child, Youth and Family says Cezar's mother has only recently moved to Auckland where a new social worker had been assigned to her.
Her two other young children are being cared for by family members.
A post-mortem has begun, which is expected to be completed on Friday, before Cezar's body is released to his family.