James Bryant, 27, told the Herald of his plan to stream Joseph Parker's clash with Solomon Haumono on July 21.
That night, a private investigator from Thompson & Toresen came to his parents' house in Auckland's Hibiscus Coast looking for him.
Bryant said he was emailed by another investigator who claimed to want his computer repaired. Suspicious, Bryant gave a friend's address and the investigator sat outside the friend's house all day waiting for him to come out before asking for Bryant's whereabouts.
He was unhappy with the private investigators' tactics.
"They've called me twice, and they told me that it's getting serious now, that it was too big to go away," Bryant said.
His father Ian contacted the Herald to express his anger at being approached by investigators.
"Please tell them not to knock on my door again at night," he said.
Duco chief executive Martin Snedden confirmed the company was using a private investigator to help with "the piracy issue".
"We won't be going into any further detail at this stage."
Media law expert Rick Shera said live-streaming and broadcasting the fight was a "pretty blatant, obvious copyright breach" and hiring investigators was a legitimate tactic.
"It's not unusual for copyright infringements to be investigated quite carefully," he said.
"If they are taking someone to court they are going to need proper evidence."
Sky TV chief executive John Fellet would not be drawn on how the company tracked down live-streamers, but said most of the information came from other people.
"I just think it's Kiwis not wanting to see other Kiwis ripped off."
Fellet didn't expect it to be an issue at the Olympics, where much of the action would be shown free-to-air on Prime TV.
Earlier, Sky spokeswoman Kirsty Way confirmed the company cut subscriptions for 10 people who live-streamed last Thursday's fight and said it was considering legal action.
Sky had taken action over live-streaming of non pay-per-view events in the past, she said.
Bryant, who said he did not broadcast last week's fight, used Facebook's Live feature to record and broadcast Parker's bout with Carlos Takam to thousands of viewers in May.
At the time, Duco director Dean Lonergan said live-streamers were "complete lowlife ****heads" and threatened to sue.
But Bryant was "not too worried".
"They've got no proof apart from the admission. I'm 100 per cent sure that there's nothing."
