The spy agency watchdog has identified a number of weaknesses in a new law for the Government Communications Security Bureau (GCSB) and the Security Intelligence Service (SIS), primarily relating to warrants.
Inspector General of Intelligence and Security Cheryl Gwyn has released her submission on the proposed legislation (PDF, 365KB).
The legislation would create the same set of rules for both agencies, in lieu of the current restriction on the GCSB intercepting New Zealanders' private communications.
Ms Gwyn said some of the new provisions were too broad, lacked safeguards or weakened conditions contained in the current law.
"My understanding is that the bill is intended to be no less stringent, and in parts stronger, in its governance of the significant powers conferred on the agencies."
In particular, she said, the requirements on the agencies to make the case that certain activities under intelligence warrants were proportionate and necessary were too weak.
"The lack of specificity in the bill's test for proportionality, compared to existing and other comparable warrant provisions, means that the [responsible] minister and Commissioner [of Security Warrants] will in some cases have little real ability to assess or control the steps to be taken.
"Public confidence requires specificity."
And she wanted agents to still have to give evidence under oath when seeking a warrant, which was not required in the new bill.
"I do not see any reason why the intelligence and security agencies, when seeking to exercise intrusive powers, should be subject to lesser requirements than agencies seeking to exercise similar or lesser powers.
"If anything there should be a higher level of formal rigour."
Agencies could obtain 'purpose warrants' at short notice, which would "not specify persons or places as targets, only the type of information sought and the purposes for which it is required".
Ms Gwyn questioned why they were needed, and whether there would be enough oversight.
"The key difficulty of purpose-based warrants is that the extent of any exercise of intrusive powers, and the targeting of particular subjects, would be left to the agency to determine.
"The external assessment of proportionality and the external authorisation of particular steps and safeguards would be lost."