Police said they made several arrests at the event on Friday in the Tasman town of Tākaka.
In a video seen by the Herald, police were forced to break up a large scuffle between protesters and Williams in the doorway of the venue holding the event.
A witness, who did not wish to be named, claimed the fracas started when a protester with a sign came and stood outside the venue door talking to a security person.
The witness also described how a local woman was punched and had her arm trapped between the door frame and the crush during the fracas.
"I talked to her afterwards and her face was bleeding and she was visibly shaking."
It was one of many incidents that reportedly occurred during the meeting.
According to the Stop Co-Governance event report, three people were removed from the hall for protesting the event.
One person began singing and then accused tour founder Julian Batchelor of "only coming to get your money."
Two others attempted to force their way into the building, wanting to know the identities of those in attendance.
Another video showed one protester throwing flour on Williams while he was outside and him describing it as disgusting and "This is what these animals do."
Williams was later arrested by police for his role in the scuffle.
He confirmed on his YouTube channel that he had been arrested. Williams is known for posting extremist and conspiracy content on his channel.
Batchelor said Williams isn’t associated with their movement.
"He has turned up to several of our South Island events," he told the Herald, "But he is not associated with the countrywide movement."
"We’re not going to filter people based on their beliefs, it’s an opportunity for people to come and learn about the treaty."
Police said they responded to a report of disorder and inquiries into the incident are ongoing.
The controversial tour has resulted in several bookings being cancelled, often at the last minute, while organisers have also struggled to find venues willing to host meetings.
By David Williams
