The Ministry of Civil Defence has been heavily criticised its response to a recent tsunami warning saying its systems for informing the public "unravelled" during the alert.
The alert followed a magnitude 8.0 earthquake at 6.48am on 30 September (NZT), which triggered a tsunami in Samoa, American Samoa and Tonga.
Two reports, an external one looking at how the ministry kept the public informed and an internal review of its operations, have been issued by Civil Defence Minister John Carter.
An external review has heavily criticised the ministry's response, saying its systems for informing the public "unravelled" during the alert.
The internal investigation found the duty earthquake scientist was given a pager to receive early alerts, when they were actually sent via email.
It also shows there was confusion about which employee at the Department of Internal Affairs should update the media.
The external review says the emergency system was undermined because public information was incoherent.
However, the report says the public and the media need to accept there will be an early 'lag time' as scientists confirm information.
The external review was conducted by former Secretary of Foreign Affairs & Trade Simon Murdoch.