UEFA president Michel Platini has sanctioned an "internal investigation" into why the referee of Manchester City's game at CSKA Moscow did not follow protocol following claims of racist abuse.
City midfielder Yaya Toure urged UEFA to act after he told referee Ovidiu Hategan he believed he was being racially abused by CSKA fans during his side's 2-1 Champions League Group D win at the Arena Khimki.
The Ivory Coast international then warned on Friday that black players may consider boycotting the 2018 World Cup in Russia unless the issue is addressed properly.
While CSKA officials insist there is no case to answer despite Toure's claims, disciplinary proceedings have been opened against the club by UEFA.
Romanian referee Hategan and his fellow officials will also be the subject of an investigation after they failed to execute the "three-step protocol" established by UEFA.
At the first sign of racism the referee is to stop the game and issue a public address to the fans requesting the behaviour desist.
The second step will then be executed if the racist behaviour does not end after the game has been restarted, with the match halted further and the teams sent to the dressing rooms.
If the racist conduct continues following this measure after play has been resumed once more then the third and final step is for the match to be abandoned.
A statement read: "UEFA will publish the findings of this internal investigation once the disciplinary case has been dealt with by UEFA's independent Control and Disciplinary Body on 30 October."
Meanwhile, CSKA Moscow star and Toure's Ivory Coast team-mate Seydou Doumbia has denied quotes that were attributed to him saying his compatriot was misguided in his comments.
In a statement on his Facebook page, Doumbia stressed: "I want to clarify my position after my Ivory Coast teammate and friend Yaya Toure accused CSKA fans of racism.
"I want to insist that I did not talk to any journalist about these facts so none of the quotes you read in the press came from me."