The investigation uncovered plots to spread misinformation about the Covid-19 vaccination and plans to influence political parties.
The group recently tried to establish August 9 — yesterday — as White Lives Matter Day, with banner drops and poster runs before the day.
Weir, who is non-binary, said the investigation was as interesting as it was toxic.
In the past six months, Weir spent time meeting, chatting online to and performing far-right activism with members of the group.
Pretending to be a hateful person took a toll on them and there were several occasions where they thought they had blown their cover.
"I'm not an actor," they said.
"It's stressful pretending to be a hateful person."
They said seeing extremely hateful views and having to echo the group regularly desensitised them to the things they saw throughout the day.
What used to upset them quickly became tame in comparison.
They had joined the group in putting up posters in Dunedin and a large banner in Wellington.
They undertook the investigation to help slow the spread of hateful misinformation.
The group existing and being vocal in a public place was enough to do harm, Weir said.
Deplatforming hate groups was essential as it created a barrier that stopped impressionable people from being indoctrinated.
The group did not have an active Dunedin presence, but it wanted to expand its influence more throughout the city.
"They're not going to succeed, I can tell you that," Weir said.
"Especially not after this."
