Scott Sinclair has posted a picture on social media showing the alleged racist abuse he suffered during Saturday's Old Firm derby.
The Celtic winger posted a still from footage of the game at Ibrox, with Celtic beating Rangers 5-1, apparently showing a man making a monkey gesture.
Sinclair, who scored the opening goal from the penalty spot, accompanied the picture with the message #notoracism.
A post shared by Scotty Sinclair (@scotty__sinclair) on
Police are investigating, with a spokesman saying: "We are aware of that incident and inquiries are ongoing.''
Writing on Twitter on Saturday, former Manchester City and Swansea wideman Sinclair said: "What a team performance yet again, the fans were right behind us from start to finish.
"Just a shame to end the game and seeing the ignorance of people no matter what team u support there is just no need for racism!''
Eight people were arrested following the match including a 23-year-old man for allegedly running on to the pitch to confront Celtic captain Scott Brown.
Two men aged 36 and 16 were arrested in connection with allegedly trying to enter the ground while drunk while a 30-year-old man was held in connection with alleged offensive behaviour.
Three men aged 34 and 53 and a 15-year-old boy were arrested in connection with alleged breach of the peace while a 16-year-old was arrested for allegedly being in possession of alcohol at the ground.
Police announced on Sunday that they had made another arrest following the incidents at the ground.
A 28-year-old man has been detained in connection with an alleged offence under the Offensive Behaviour at Football and Threatening Communications Act, officers said.
The man is expected to appear at Glasgow Sheriff Court on Tuesday.