The SIS spy agency has been told to prepare for more demand for its intelligence to be used by police in counter-terrorism criminal cases.
The police and SIS work closely on counter terrorism, but spy agency intelligence is rarely used in court - even if it has evidential value.
However, in a new report, the Inspector-General of Intelligence and Security said this was changing.
"This position already looks out of date and inconsistent with recent developments," Brendan Horsley said.
"Intelligence gathering has not traditionally been conducted with an expectation that it meets the evidential standards that apply in criminal investigations, or that it may be disclosed to the defence as part of the criminal disclosure process."
But law changes, particularly last year with the Security Information in Proceedings Act coming into force, would change that, he said.
The SIS and police cooperated well already.
"The police and NZSIS have established a joint leads process to triage and share lead information.
"The service conducts CT discovery projects to find new investigative leads and identify previously unknown threats. The police support NZSIS projects, where they hold relevant information, by sharing it with the service."
The agency had made improvements, but "I think it has more to do" in the face of a likely rise in demand for its intelligence as evidence, Horsley said.
"It will need to update its processes for sharing intelligence with police. The service will need to train its operational staff on what is required, in investigations, to meet evidential standards."
Record keeping about interactions with police was too ad hoc.
"When information is shared at a formal meeting, the discussions, actions, and responsibilities are minuted.
"NZSIS record-keeping practices for other developments in investigations, eg intelligence shared with or received from police, are not prescribed in policy and are variable.
"I expect that to improve its record-keeping."
The agency told him some of its intelligence teams regularly considered potential use of intelligence as evidence, and sought legal advice case-by-case.
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