An inmate who killed a prison officer at Springhill Prison in north Waikato has been sentenced to six years and four months in jail.
Latu Kepu, 22, pleaded guilty to the manslaughter of Jason Palmer after punching him in the head as he was being let out of his cell in May this year.
The 33-year-old officer fell to the ground and died in hospital the next day.
In sentencing Kepu in the High Court in Hamilton on Friday, Justice Heath described the attack as "cowardly" and said the only mitigating factor was the fact that he pleaded guilty.
Justice Heath said the sentence was to denounce the crime and deter others from assaulting prison officers.
Kepu must serve a minimum period of just over four years for the manslaughter charge.
The sentence will take effect once Kepu finishes his current jail term of two years and eight months for assaulting a police officer and a pregnant woman.