A soldier is in hospital after a round exploded in the machine gun he was using at Waiouru military base.
A spokesperson for the Defence Force, Major Kristian Dunne, says the soldier was using a C9 light machine gun during a live firing field exercise.
A round exploded in the barrel and a bullet casing came out, hitting the man in the shoulder.
Major Dunne believes the incident is the first of its kind in New Zealand.
C9 light machine guns are the most commonly used light support weapon in the New Zealand Army.
The solder is reported to be in a stable condition and a court of inquiry has begun.