A baby boy remains seriously ill with a fractured skull at Starship Hospital in Auckland as police continue inquiries.
The four-month-old baby was taken to Nelson hospital from its Motueka home on Monday before being transferred to the children's hospital.
Detective Sergeant Kevin Tiernan says the baby's injuries are not accidental.
Mr Tiernan says the parents and others who were in the baby's home over the long weekend have been interviewed, but it is too early to speculate about possible charges.