Searches carried out by police following the Christchurch mosque attacks have been deemed unlawful by the Independent Police Conduct Authority (IPCA).
They were part of an operation targeting people of interest to national security after the 15 March attacks last year.
The IPCA said says the searches generated a number of complaints and of those it investigated, three were found to be unlawful.
Canterbury District Commander John Price said police acknowledged the findings on the legal powers of search and seizure in two of the three cases, and would be looking to work with the authority to seek a solution.
"These searches were part of a significant national security operation, conducted in the aftermath of the terrorist attacks on two Christchurch mosques," Price said.
"I am confident that the officers involved in these three searches were acting with the best of intentions, and were absolutely focused on mitigating risk and preventing further harm in our community."
Police had formally apologised to those involved, he said.