Police are investigating the death of a baby who was found at Whanganui Hospital last Friday.
They have been trying to establish the circumstances which led to the 16-month-old's death.
Detective Inspector David Kirby said the death was sudden and a post-mortem was completed on Saturday.
Mr Kirby said officers were speaking with the baby's family and hospital staff and they were not looking for anybody else in relation to the death.
He said police have notified the coroner.
Police were not commenting on a suggestion the baby was left in a car.
A spokesperson from the Whanganui District Health Board said their thoughts were with the family in their time of grief.