A Hawke's Bay Regional Prison inmate was in a serious condition in hospital today after being attacked by fellow prisoners over the weekend.
The Department of Corrections said the man was "seriously assaulted" in the incident on Saturday.
Prison manager George Massingham said the assault has been referred to police and the department expected criminal charges would be laid against the perpetrators of the attack.
Corrections said it would not comment further on the incident given it was now being investigated by police.
A police spokesperson confirmed the assault was being investigated and said inmates were interviewed by officers today in relation to the incident.