The Inspector-General of Intelligence and Security, Cheryl Gwyn, has criticised the SIS for failing to provide her with copies of visual surveillance warrants.
She says in her annual report, released today, that two warrants were issued in the year to June under new powers which came into effect in December.
The Security Intelligence Service should have provided copies to her office "as soon as practicable" but that didn't happen.
"Instead, the warrants and their supporting documentation were subsequently identified as part of my office's regular warrant review process," she says in the report.
"In response to that incident, NZSIS has now instituted appropriate arrangements to ensure that I am provided with a copy of any warrant issued, on the day of issue or on the next working day."
Ms Gwyn also found fault with the spy agency's compliance procedures - the way it ensures it's meeting its legal obligations.
"The absence of structures and policies meant that NZSIS staff, despite their best intentions, were not sufficiently supported to ensure compliance," she says in her report.
"For those reasons, I cannot conclude that NZSIS has sound compliance procedures and systems in place."
She says the SIS is making efforts to change its systems.
The Green Party says the SIS didn't comply with the law.
"At the very least, these new powers have to go," said co-leader James Shaw.
The Greens opposed the visual surveillance powers when they were introduced.