A former rugby league star has condemned an alleged assault on a coach saying "it's just a game, not the NRL".

Henry Fa'afili's comments come after police and the Bay of Plenty rugby union have announced an investigation is underway after a parent allegedly assaulted a coach at the Baywide Secondary Schools competition last weekend.

A Bay of Plenty rugby union statement on Tuesday said the union's coach development manager Dan Goodwin would reach out to the person who was allegedly assaulted to offer support.

The union said it was working with the schools and was offering support to all involved. It would not comment further until the police had finished their investigation.

A police spokeswoman confirmed police received a report of an assault and were making inquiries into the incident. No charges had been filed at this time.

Former Warrior and NZ Rugby League and NRL ambassador Henry Fa'afili. Photo / Supplied

Fa'afili, who is a former Warrior and NZ Rugby League and NRL ambassador, said the alleged assault was "very poor form" and the rugby field should be a "safe" place for kids to play.

"There's a lot of kids around ... it's not teaching the kids anything about good sportsmanship.''

Fa'afili, who is also the head coach and trainer at the Tauranga Boxing Academy, said coaches in secondary schools were often volunteers.

Asked how these incidents could be stopped, Fa'afili said it was sometimes the "parents that need the education".

"I think it's them that needs to know it's just a game - it's not the NRL. These coaches and referees are all volunteers. You want to make it safe and make it a happy place where kids want to come and enjoy playing.

"But if you get that kind of stuff happening around us, it's poor to see, and it's sad to see actually as well.

"It's not a good example we're trying to set our secondary school kids."

Tauranga Sports Rugby Club director of rugby John O'Loan said in his view, incidents such as this were "far and few between".

"You don't really see a lot of it in senior rugby but you might see a little bit of it in [junior rugby] and it really is dependent on the club's culture and the way that they probably observe sideline behaviour and what they do about it."

O'Loan said the senior side were those aged 18 and older and the junior side were those aged 13 and under.

He had never had a complaint about "sideline behaviour" at his club.

"At the end of the day, you can't stop an angry parent. I don't think it sits with the club, it actually sits with the parents.

"Coaches, referees, administrators - we're not here to get into a fight or an argument on the sideline because we've got children involved or whatever. It's generally the angry old parents that come along and get overly zealous about things."

Te Tuinga Whanau Support Services executive director and stalwart Te Puna Rugby Club supporter Tommy Wilson. Photo / George Novak

However, Te Tuinga Whanau Support Services executive director and stalwart Te Puna Rugby Club supporter Tommy Wilson said in his view, an increase in "on-field violence" was happening everywhere in New Zealand.

"That's because it's being glorified on social media.

"As soon as someone gets in a scrap, it's being posted up and everyone thinks it's cool. Well, guess what, it's not cool."

Sport Bay of Plenty chief executive Heidi Lichtwark. Photo / Supplied

Sport Bay of Plenty chief executive Heidi Lichtwark said "poor sideline behaviour" had a negative impact on participation in sport.

"It's absolutely terrible to think young people may be driven away from sport because the adults around them have created an environment that's no longer enjoyable or focused on their needs.

"We're losing young people from sport, and as a result they're missing out on the opportunity to be active."

Lichtwark said creating a great sporting environment for young people was a collective effort and every adult in sport had a role to play.

"If we're going to change this we need to improve what's happening at the grassroots, and adults have to start thinking and acting differently and in ways that support the needs of young people.

"Attitudes and behaviours need to change."

In May, NZME reported 17 complaints of misconduct or foul play at various age group levels had been reported to the union across the region over two weekends.

In one on May 7, a Rangataua Premier player allegedly elbowed a player from the opposing Te Puna team and that player suffered a broken jaw.

A complaint by a Te Puna Club representative, supported by witness statements, was upheld by the union's disciplinary officer at a hearing on May 13.

The accused player was suspended for 12 weeks, including from sideline duties such as passing out water bottles to teammates.

What's the score?

The scoreboard at the Steamers' match on Sunday. Photo / Supplied

Tommy Wilson went to the Steamers' match on Sunday at the Tauranga domain.

"The rugby was sparkling, the sunshine was sparkling but sadly you couldn't see the score.

"We were all asking each other, what's the score?"

Wilson said the scoreboard had been broken down for "months".

"All they had was a screen ... if you're standing below the screen you can see it because it's about a foot by a foot but nowhere on the ground could you see the score or know how much time was left.

"It was a great day but surely something as simple as a scoreboard can be rectified by the Bay of Plenty Rugby Union."

Wilson said the Steamers were playing again next weekend.

"Hopefully they'll have a scoreboard up by then."

In response, Bay of Plenty Rugby Union community engagements and relationships manager Neil Alton said the scoreboard belonged to the Tauranga Sports Rugby Club and a joint collaboration between Tauranga City Council, Bay of Plenty Rugby and Tauranga Sports Rugby Club last year failed to raise the $15,000 repair cost.

"While the score is on the big screen, we realise this can't be seen from all areas of the venue so for the remaining four home games, the Bay of Plenty Rugby Union will be bringing in a temporary digital scoreboard to replace the broken scoreboard and clock so that our fans can be kept up to date with the score and the time left to play."

Tauranga Sports Rugby Club director of rugby John O'Loan said the scoreboard did not work "properly" but for a local club game, "it's fine because we know what's happening".

"It's probably only sufficient for a club game - it probably wouldn't be sufficient for a Steamers' game or a crowd that size.

"It's kind of a digital screen but the numbers need to flip over and there are certain parts of one number that doesn't, so sometimes an eight might look like a six."

O'Loan said the club had found a sponsor who could contribute to "completely" upgrading it, which would probably take place "in a year or so".