New Zealand SIS agents spied without a warrant by using an rarely used act reserved for the prevention of a terrorist act.
A release by the New Zealand Security Intelligence Service shows it used a Section 41D Authorisation which enables the spies to carry out surveillance in an "emergency situation".
The legislation, the Security Intelligence Act 1969, says use of the power is necessary for detection, investigation, or prevention of any actual, potential, or suspected terrorist act or facilitation of a terrorist act".
It was used sometime in the six months between July and December last year.
Minister responsible for the SIS Chris Finlayson confirmed use of section was "rare".