A prisoner has been found dead in his cell in Auckland Prison at Paremoremo.
The man was found this morning by staff on their routine rounds, the Department of Corrections says.
Auckland Prison director Tom Sherlock said emergency services were called but the man was pronounced dead at the scene.
Mr Sherlock said early indications were that he died of natural causes.
He said the death had been referred to the coroner and would be investigated by the Corrections Inspectorate and the Police.