The 60-year-old is due to appear in the Ohakune District Court on Friday in connection with McNaught's death.
Walton boxing coach Raymond Richards said he was probably the last person to speak with McNaught, who he had known for about four years.
"He was leaving to go home, we had a chat while he was putting on his gear and then he got on his motorbike and headed off," Richards said.
Sometime later Richards was contacted by friends, who had been trying to get hold of McNaught on his cellphone, and they gave him the bad news.
"It was devastating. He was a wonderful man, a tremendous asset to the club and devoted to the boxers."
Richards said McNaught had a "heart of gold" and helped prepare Alex Mukuka, NZ lightweight champion, for the Birmingham Commonwealth Games which open on July 28.
"He is one of those volunteers who pitches in and can't do enough.
"It was just so devastating and such a loss to his large family, the club and the wider community."
He had a passion for the sport, could spar with anyone from a 10-year-old through to a heavyweight and the club planned to honour his memory by establishing the Brett McNaught Memorial Award for Sportsmanship.
A celebration of McNaught's life was held at the Matamata Racecourse on April 30, while tributes flowed on the club's Facebook page.
"Our deepest and warmest condolences to Brett's whānau, friends and the team at Waltons Boxing Club xo," one wrote.
"Our family is new to the club but Brett welcomed and encouraged my boy to be his best."
"Rest in love n light Brett," another posted.
The road was closed for almost six hours as police examined the scene.
Richards said McNaught's death was a tragic loss and he would be sadly missed.
