Police have made no arrests after thousands gathered at the Auckland Domain and marched around neighbouring streets, but say they will be prosecuting "a number of individuals" in the coming days.
About 5000 people gathered in the domain in breach of alert level 3 restrictions, before marching to Newmarket and back.
Superintendent Shanan Gray said police are "once again extremely disappointed" by those who took part in the gathering.
"While those in attendance generally conducted themselves in a calm manner, the gathering was a significant breach of Covid-19 alert level 3 requirements.
"We recognise that individuals have a lawful right to protest however this should not be at the expense of restrictions designed to keep our community safe."
He said police were frustrated by the disruption caused to members of the public.
"The health risk posed to attendees as well as other road users was unnecessary and unacceptable.
"No arrests were made today however police will be taking prosecution action against a number of individuals in the coming days."