Prisoner facing murder charges after alleged fatal assault on fellow inmate at Auckland South Corrections Facility

An Auckland prisoner has been charged with murder after the alleged fatal assault of a fellow inmate on Thursday.

Detective Inspector Warrick Adkin, of Counties Manukau, said the 47-year-old was due in the Manukau District Court next week - charged with murder and wounding.

"We have advised the deceased man's family of this development and our thoughts continue to be with them," he said in a statement.

Another person was seriously injured in the attack, which took place in the kitchen of the Auckland South Corrections Facility.

"The surviving victim remains in a serious but stable condition in hospital," Det Insp Adkin said.

Police could not comment further as the matter was before the court, he added.

Serco, the private firm that operates the prison, said violence in the facility wasn't tolerated.

A Serco spokesperson said the firm would ensure "all evidence, including CCTV footage, is provided to police".

"Assaults in prison are illegal, unacceptable and we do not tolerate them. Any perpetrators should expect to face criminal charges as well as prison disciplinary processes."