Prime Minister John Key gave an assurance yesterday that New Zealand's spies in the SIS and GCSB could not gather information about a person from various databases and then apply for a warrant after the fact.
He made his comments at his post cabinet press conference amid groups such as the Law Society expressing concerns about a bill that expands spy powers for agents at the Government Communications Security Bureau and another bill that allows the Government to expand the types of organisations that must co-operate with spy agencies for interception purposes.
"They don't have the authority to simply put in techniques to exfiltrate information and then backfill that with legal justification for doing so via warrants," Mr Key said.
"In other words they can only access information when they are legally entitled to do so, and they can't circumvent that process by gathering information upfront. They have to do that reactively, not proactively."
Mr Key has previously said New Zealand agents acted lawfully but is usually short on detail.