The chief of the Defence Force has apologised to the family of an Air Force sergeant who died while on duty.
Sergeant Andrew Forster, 46, was killed instantly when an artillery shell exploded at Waiouru Military Camp in November last year.
A Court of Inquiry found procedures for marking unexploded ammunition were not strictly followed.
But Lieutenant-General Jerry Mateparae says the Defence Force should have done more to explain the findings.
He says they show there was no evidence to determine what led to the detonation and it is liklely that a cause will never be known.
Lieutenant General Mateparae says Sergeant Forster's family was hurt and frustrated that people have concluded he was to blame and the Defence Force will do better in future.