Civil Defence has mistakenly put out a warning for a magnitude 6.6 quake that reportedly hit south of the Kermadec Islands.
Just before 4pm today, it sent out a message to say it was assessing the tsunami risk for New Zealand after a 6.6 magnitude quake was recorded south of the Kermadec Islands.
However, a few minutes later it deleted the tweet and said it was an old earthquake notification - there was no event today.
Civil Defence has been calling people to apologise and it is assessing how it happened.
Civil Defence director Sarah Stuart-Black told Checkpoint the incident would be investigated to make sure it didn't happen again.
"I can confirm there is no current earthquake event and there's no need for concern."
The message was sent out from a training site. She said she would be looking at what went wrong from the "technology point of view".
"We're trying to work out what exactly occurred and why a duplicate message of an old event was sent out," Ms Stuart-Black said.
"It wasn't a tsunami notification and it didn't involve any instructions to evacuate.
"I apologise for any confusion or alarm the message may have created by being sent out."