"The Authority is fully independent of Police."
Mr Williams said Te Kotahi o Tuhoe's writs - seeking compensation, aggravated damages and legal costs - would be served on the attorney-general.
The attorney-general is responsible for the actions of state departments, including the police.
No specific sum was being sought, with Mr Williams saying that was up to the court to decide.
The legal action related not to those who had been arrested, but to others, including women and children, affected by the police operation.
Police arrested 17 people in raids around the country but the focus was on Ruatoki, about 20km south of Whakatane, where police alleged terrorist camps were being run.
Solicitor-General David Collins has since rejected an application to mount a prosecution under the Terrorism Suppression Act. Instead, most of the 17 face firearm charges.
Mr Williams said the writs would be filed because there had been no reply to a written approach to Police Commissioner Howard Broad last month to settle the issue out of court by way of apology and compensation.
- NZPA