A report on the country's spy agency has found it's been completely compliant with the law for three years running.

In 2013 a review of the GCSB recommended a number of changes be made to the bureau, to ensure what it was doing was legal.

It followed the US spying scandal on Kim Dotcom's home that year, which later saw him take the GCSB to court over his right as a New Zealand citizen to be protected from surveillance.

The GCSB's director general Andrew Hampton says that review found there wasn't a strong understanding by staff working within the bureau, around what was and wasn't legal.

He's pleased with how the agency's turned that around over the past three years.

Mr Hampton says they've really worked on a compliance culture within the organisation so that everyone, no matter what their role is, understands that it's fundamental they act within the law and the New Zealand national interest.