Sawt Falasteen - Australian rugby league star accuses rival of racial slur in US showcase

Brisbane Broncos back Ezra Mam alleged that Sydney Roosters prop Spencer Leniu made the remark during Sunday's season-opener in Las Vegas.

The matter is being investigated and Leniu has been charged with contrary conduct, the National Rugby League (NRL) said.

There have been previous instances of racial abuse in the NRL but that was from spectators.

Mam reported the alleged slur to match referee Adam Gee, who put Leniu on report, the NRL said.

Brisbane's players later confronted Leniu in the corridors of the teams' hotel in Las Vegas, The Sydney Morning Herald reported.

Broncos coach Kevin Walters said after the game, which the Roosters won 20-10, that Mam was "pretty upset".

"We support Ezra. He's adamant," Walters told reporters when asked about the comment.

"We'll leave that in the hands of the NRL to police and adjudicate on."

The match was part of a double-header of NRL games which drew a crowd of 40,000 to the Allegiant Stadium. The Las Vegas venue hosted the Super Bowl last month.

Sydney Roosters coach Trent Robinson said he had spoken to Leniu, a Samoa international, about the match but not the allegation. Robinson said the matter needed to be investigated fully.

"Ezra's adamant? That doesn't mean it's right," Robinson told reporters.

"He obviously made the complaint but that doesn't mean that it's right. It'll go through the formal process as it should."

Last March, South Sydney's Indigenous player Latrell Mitchell was racially abused from the crowd at half-time during a match at the Penrith Panthers.

In an Instagram post, Mitchell demanded the NRL take action over the Mam incident.

"I stand with you Bala. NRL better deal with this," he wrote.

J.AbuHassan--SF-PST