The NRL is investigating an alleged racial slur directed at Indigenous South Sydney stars Latrell Mitchell and Cody Walker during a game on Saturday night.

The Rabbitohs released a statement saying the league's integrity unit is investigating after Mitchell and Walker were allegedly racially vilified during Saturday night's 28-14 loss to the St George Illawarra Dragons at Kogarah Stadium.

"The Rabbitohs were informed of the incident by a member of the public as well as the NRL. The NRL has confirmed the NRL Integrity Unit is investigating the matter," the statement read.

"The Rabbitohs stand in condemnation of any form of racism in our sport, and society in general, and will support the NRL's investigation in any way possible."

A fan was last year banned from attending NRL games after racially abusing Mitchell at a game in Penrith.

Two men were also charged for online racist abuse directed at Mitchell in 2021, and he called out racist comments on social media when he was playing for the Sydney Roosters back in 2019.

Mitchell and Walker also spoke vocally in support of Ezra Mam after the First Nations star made a formal complaint against the Roosters' Spencer Leniu for calling him a "monkey" on the field during the first-round match between Sydney and Brisbane.

Leniu was suspended for eight weeks and made his return against the Warriors on Sunday.