More than 50 Immigration New Zealand staff have been found to have accessed confidential client information without authority since the agency started its internal investigations process in 2004.
Over the past nine financial years, there have been 49 substantiated complaints, involving 51 staff breaching privacy guidelines at the agency - but Immigration NZ insists the number is "very small".
One complainant, who was told after a Department of Labour investigation in April that his client records had been accessed by his ex-wife, a former immigration officer, says the practice has been "going on for years".
"When we were still together, I used to accompany her to Immigration functions, where one of the most frequent things they talked about [was] new information that they had found in client files," he said.
"My ex-wife was working at Immigration a decade ago. Privacy breaches have been going on for years and what we're seeing is that nothing's changed."