Rabbitohs officials have confirmed a teenage fan allegedly targeted Mitchell with a racist slur as he walked up the tunnel at half-time during Souths' 16-10 loss to Penrith on Thursday.
The fan allegedly left the scene after making the comment but a man who was sitting with him - said to be his father - was ejected by security.
The spectator in question wore the jersey of an NRL club that did not feature in the fixture, according to a Rabbitohs spokesperson.
A proud Birrbay and Wiradjuri man, Mitchell has faced racial taunts in the past and in April 2021 two men were charged for sending him racially abusive social media messages.
Cleary, who has played alongside Mitchell at state and international level - most recently at the Rugby League World Cup - was stunned by the incident.
"It's just disgusting," Cleary said.
"There's no point in a game where you should feel like you have the right to say stuff like that to a player.
"I hope they never come back here. They're not fans if they're saying that stuff."
The incident is the second reported case of racial abuse at Bluebet Stadium, after a fan targeted Greg Inglis with a similar slur in 2018.
NRL CEO Andrew Abdo threw his support behind Mitchell late on Thursday night, while Souths coach Jason Demetriou said his club would report the matter to police.
"This is not something Latrell just cops on the footy field, this is something he's had to deal with his whole life. All Indigenous people do," Demetriou said.
"I can't get my head around it to be honest, I don't understand in Australia how anyone can be raised like that.
"There has to be hard and fast rules, if anyone comes close to getting racial, they are completely ruled out of our game. If it's a young kid, pull his parents out as well. It's just not on."
Despite the incident, Mitchell finished the night as the Rabbitohs' best player afield and had a hand in two late tries that put the game back within the visitors' reach.
14°C