Gold Coast forward Tyrone Peachey has accused Barnett of racial abuse during the second half of the Knights' final round 36-6 loss to the Titans on Friday night.

It's understood the NRL Integrity Unit, which is conducting the investigation, has looked at footage and listened to available audio of the alleged incident and were hoping to interview both players over the weekend.

Barnett will face a hefty suspension and/or fine which would almost certainly end his hopes of playing in his first finals series if he is found guilty of the alleged offence.

Peachey claims Barnett called him a "black c***" when the pair came together in a tackle during the second half of the game on the Gold Coast.

At the time, Peachey complained to referee Chris Sutton, saying: "That backrower just called me a black c***".

When asked several times by Sutton if he wanted to make an on-field complaint about the incident, Peachey declined and walked away. Audio of his conversation with the referee was picked up by broadcaster Fox Sports.

The two players have been in contact with each other since the game but hold differing views of what was said.

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While Barnett has been gagged by the Knights from making any public comment, Peachey did not hold back in an interview with News Corp over the weekend.

"I know exactly what I heard, and that's why I reacted the way I did," he said. "It can be put down to ignorance, heat of the competition or lack of education. Either way, I won't stand for it. Those things are not okay to say."

Barnett is said to have been stunned by the racism allegation with those close to him saying he is hoping there is audio of the incident that will completely clear his name.

For their part the Knights issued a statement on Saturday which read:

"The Newcastle Knights are assisting the NRL following a racial abuse allegation made against one of its players in the Round 20 match against the Gold Coast.

"The club is conducting its own investigation into the claims and working alongside the NRL Integrity Unit. Racism and vilification have no place in the game and as a club, the Knights support a tough stance against anyone who feels that sort of behaviour is acceptable.

"The club has been in dialogue with the Titans overnight [Friday] and the two players involved in the alleged incident have also spoken. With the matter before the Integrity Unit, the club will make no further comment."

An NRL spokesman told the Newcastle Herald yesterday that putting a time-frame on the investigation at this stage would be guess-work.

"It could be quite quick or it could take a few days to be resolved," the spokesman said. "But I wouldn't expect it to drag on for too long."

Any delay in the outcome of the investigation won't help the Knights cause. They have to find a way to bounce back from their worst defeat of the season, a result that cost them a home final, and rediscover the belief to upset the in-form Rabbitohs to keep their campaign alive.

The Bunnies, after their crushing 60-8 win over defending premiers Sydney Roosters, have been installed a $1.37 favourite with Sportsbet for the game with the Knights the $3.10 outsider.