A prisoner has admitted stomping on the head of a murderer in the country's maximum security prison at Paremoremo.
Nigel Lake appeared at the High Court in Auckland today, where he admitted a charge of wounding with intent to cause grievous bodily harm.
Nikki Roper was left with a fractured skull and broken arm following the attack in July. He now has a titanium plate in his jaw, and suffers hearing loss and nerve damage.
He is serving a life sentence for murdering his former girlfriend Alexsis Tovizi in 2010.
Another man, Stead Nuku, has also admitted a charge of causing grievous bodily harm, when he broke Roper's arm.
Nuku and Lake are due to be sentenced in February.