Police in South Auckland have launched an investigation after a 10-week-old child was critically injured in Papakura.
The child was injured earlier this week.
Police said they were notified by medical staff about lunchtime on Tuesday but would not provide details about the baby's injuries due to privacy reasons.
The baby boy suffered serious injuries and is in a critical condition at Starship Children's Hospital.
The child was taken to hospital on Tuesday, but it is not known whether the incident happened on the same day.
Police would only say there had been an "incident'', and would not discuss the nature or circumstances of what occurred.
Detective Inspector Colin Higson of Counties Manukau Police appealed to anyone who might have any useful information to the investigation to come forward.
"We are making enquiries into this incident and ask anyone with information to contact police."
Can you help? Contact Counties Manukau Police on (09) 261 1321 or Crimestoppers anonymously on 0800 555 111.