Three prisoners who violently attacked their guards will spend an extra three and a half years in jail.
Dickie Pani-Marsden, 23, Stead Nuku, 24 and Arthur Duncan Briggs, 26, all pleaded guilty to 13 charges after the attack in the maximum security wing of Auckland Prison at Paremoremo in October last year.
A fourth prisoner, Patrick Waru, was sentenced in June to seven years and 10 months for his part.
At the time Pani-Marsden, then 22, was serving a seven year sentence, Nuku was serving more than eight years for various offences including assault and Briggs had a decade of prison time.
At the High Court in Auckland this morning, Justice Lang said the attack was premeditated and that Waru had asked officers for a bucket and mop to gain access to their area.
He said Waru attacked them with handmade weapons strapped to his hands before Pani-Marsden, Nuku and Briggs joined in.
"This resulted in four other prison officers being called to the area and a sustained incident involving significant violence then occurred.
"One of the guards was stabbed in the neck, one had his head and body stomped on, and another was king hit in the head.
"Thankfully their protective clothing prevented them from receiving more serious injuries," he said.
He said the group were equally to blame.
"Although you were not carrying weapons yourselves, you knew that Mr Waru was carrying two weapons and you knew he was likely to use them.
"You must also have been aware that the incident was inevitably going to spread and become one of significant proportion."
Before the group's sentences were handed down, Pani-Marsden's lawyer Emma Priest told the court there should be some minor reduction for her client's age and efforts to educate himself in prison.
"It is submitted that there are significant issues in Mr Pani-Marsden's background and that he can be distinguished from his co-defendants on the basis that he is very much the youngest of them, arguably more impressionable and influenced by them.
"He's made significant efforts in my submission towards those very much self-directed goals in terms of literacy and numeracy."
Briggs's lawyer Susan Gray said her client was not making excuses for his behavior, but submitted he had little support in prison.
"He has a propensity for violence and that's why he was incarcerated for this lengthy period in the first place.
"But in the 10 years he's been in jail so far he has not been offered any rehabilitation at all.
"He's in this vicious cycle of having a propensity for violence that is left untreated and so his behavior could be arguably be said to be inevitable."
Justice Lang also told Briggs he was on his final warning under the three-strikes legislation and any further offending would result in the maximum sentence.
Justice Lang sentenced Pani-Marsden to three years and eight months in prison, with Nuku and Briggs sentenced to three years and ten months.
The new jail terms will be served cumulatively with their existing sentences.