Police have arrested a ninth person following Saturday's Old Firm match at Ibrox.
A 28-year-old man was detained in connection with an alleged offence under the Offensive Behaviour at Football and Threatening Communications Act.
It comes after officers said that were aware of a racially motivated incident.
It is understood someone allegedly made a monkey gesture at Celtic player Scott Sinclair.
The 28-year-old man is expected to appear at Glasgow Sheriff Court on Tuesday.
On Saturday, police said eight people had been arrested in connection with alleged offences in and around the stadium.