Boshier said the meeting requirements could not be avoided simply by calling what was really a meeting a "workshop" and he was concerned the public would grow suspicious if councils repeatedly used workshops to discuss issues.
"Local bodies are not allowed to exclude the public from meetings so they can hold 'free and frank' discussions behind closed doors. Yet I fear this may happening."
He said councillors were elected to provide a voice for their communities and they should feel free to express their opinions in the same way robust exchanges occurred in the debating chamber of Parliament.
The eight councils were chosen for a variety of reasons, and Boshier said some were doing the right thing and he wanted to share good practices with other councils so they could learn from the investigation.
Rangitīkei District Council has been contacted for comment about its inclusion in the investigation.
The other seven councils part of the investigation were Rotorua Lakes Council, Taranaki Regional Council, Taupō District Council, Palmerston North City Council, Waimakariri District Council, Timaru District Council and Clutha District Council.
In October last year, the Rangitīkei District Council planned to hold a Finance and Performance Committee meeting behind closed doors, with no live stream of the meeting being provided to the public.
Dr Dean Knight, an associate professor at Victoria University's Faculty of Law, said at the time the unwillingness to live stream the meeting was likely unlawful.
After media scrutiny, the council reached a compromise and agreed to release a recording of the meeting after it was completed and said all future meetings would be live streamed while under Covid-19 conditions.
The council did not respond to questions about why it made the call to not live stream the meeting in the first place.