Aberdeen have accused Celtic's Aleksandar Tonev of making a racist slur during their Scottish Premiership match at Celtic Park yesterday.
The Dons allege that the Bulgarian winger directed racist abuse towards defender Shay Logan during their 2-1 defeat to the Scottish champions.
BBC Sport claims that Logan and captain Mark Reynolds spoke to match referee Bobby Madden about the incident, and that a report will be filed to the Scottish FA tomorrow.
Tonev, who was making his debut, joined Celtic on loan from Aston Villa during the summer.