An unsupervised staff member was to blame for Civil Defence wrongly alerting the news media to a massive earthquake and tsunami this year.
The alert in early February warned of a destructive tsunami after a magnitude 8.7 quake, which had not happened.
A memo obtained by RNZ under the Official Information Act shows the alert was sent in error by an unsupervised staffer on a training day.
It was never broadcast by the media, which queried its accuracy, and a cancellation was sent within five minutes.
Civil Defence director Sarah Stuart-Black said the person who sent the email felt devastated by the mistake. She said the person remained on staff.
Ms Stuart-Black said unsupervised training was now not permitted and a new system, going live in June, would provide a training platform where such errors could not happen.
"We have a new national warning system that will mean that it has a separate training environment so that it will never be in a live space where we could have a broadcast sent out in error."