SYDNEY — An Indigenous Australian rugby league star has accused a rival player of using a racial slur against him during a hotly anticipated game in Las Vegas.

Brisbane Broncos' Ezra Mam says Spencer Leniu called him a "monkey".

When asked about the complaint after the match, the Sydney Roosters prop said "nothing" had happened and "it's all just fun and games on the field".

Australian sports have been battling a wave of racist abuse from crowds, but incidents between players are uncommon.

National Rugby League (NRL) officials are investigating the claim, which has overshadowed the start of the season.

The two teams were facing off at Allegiant Stadium on Saturday local time - the same venue as last month's Super Bowl - as part of a marquee round aimed at enticing a US audience to Australia's top-tier competition.

During the game, which the Broncos lost 20-10, Mam can be heard telling the referee of the alleged slur, with another teammate repeating the accusation.

The referee said he did not hear the language, but made a formal complaint at Mam's request.

Leniu - a Samoa Test representative - has been charged with breaking the NRL's behavior code and will face a judiciary panel, which will hear evidence and can impose penalties including fines and match bans.

After the game, Broncos coach Kevin Walters said Mam was "adamant" the slur had been used and was "pretty upset".

"In this day and age, you wouldn't think this is still out there," team captain Adam Reynolds added.

"We certainly don't stand for racism and we'll support Ezra and get around him, make sure he's all right."

The coach of the Roosters, Trent Robinson, said he hadn't spoken to Leniu about the allegation.

"[Mam] obviously made the complaint, but that doesn't mean that it's right. It'll go through the formal process, as it should," he said.

Local media have also reported that Mam's teammates later had a verbal argument with Leniu over the incident, in a corridor at the hotel where both sides were staying.

In recent years, the NRL has struggled to address racist abuse directed at players by spectators.

Players including South Sydney Rabbitohs star Latrell Mitchell have regularly reported vitriol, both online and during games.

Mitchell -- who is also the Indigenous All Stars captain -- posted to Instagram on Sunday supporting Mam and demanding action from league officials.

"I stand with you," he said.

NRL leaders have vowed to eradicate racism from the sport, and say that anyone who racially abuses or threatens players will be reported to police. — BBC