Our electronic surveillance agency might have illegally spied on New Zealanders to a greater extent than previously revealed, Parliament has been told.
But the scale of any illegal surveillance by the Government Communications Security Bureau might remain hidden because documentation which detailed it was either not kept or is missing.
The few details of the GCSB's latest legal problem are revealed today in the annual report of the Inspector General of Intelligence and Security, Cheryl Gwyn.
The revelation opens the bureau again to allegations of sloppy handling of the world's most sophisticated surveillance technology which it uses through a partnership with the United States, the United Kingdom, Australia and Canada.
The issue emerged through an internal GCSB investigation, which is part of its obligation to ensure it is compliant with its own laws.