WEST Coast ruckman Nic Naitanui was allegedly the subject of racial abuse from a fan during Sunday's Derby loss to Fremantle.
Domain Stadium has investigated an alleged racial comment from a patron directed towards the star Eagle but the stadium cannot take the matter further unless more evidence comes to hand.
A spokesman for Domain Stadium confirmed to AFL.com.au that a fan had made a formal complaint to security staff alleging a member of the crowd had racially vilified Naitanui during the match.
Security staff attended the scene but the patron could not identify exactly where the comment came from.
The security staff remained on the scene for an extended period of time but no further racial comments were heard.
Domain Stadium stated it was unable to pursue the matter any further unless more evidence came to light.
The Eagles said they were aware the of the incident but had left the investigation in the hands of Domain Stadium.
Eagles midfielder Andrew Gaff was asked about the incident on Monday and said he was disappointed.
"Obviously (there is) a zero tolerance policy around West Coast and Domain Stadium," Gaff said.
"So it's disappointing. We come to the footy each week to support our team and hopefully they get over the line.
"It's disappointing someone has crossed the line."
A spokesman for the AFL told AFL.com.au the League was aware of the incident and that the alleged abuser could not be identified.