The Romanian fourth official Sebastian Coltescu was identifying Basaksehir assistant Pierre Webo, the former Cameroon striker, to the referee when the alleged comment was made. Webo reacted angrily, shouting: “Why did you say negro?” 

The game stopped as an argument broke out on the touchline at the Parc des Princes. Basaksehir’s substitute forward Demba Ba was heard saying to Coltescu: “You never this say ‘this white guy’, you say ‘this guy’, so why when you mention… listen to me… so why when you mention a black guy [do] you have to say ‘this black guy’?”

The Basaksehir players walked away down the tunnel and their opponents followed. There is not yet confirmation over whether the game, which was 0-0, will resume. Players from both sides were adamant they would not play on if Coltescu was still involved.

Uefa said: “Following an alleged incident involving the 4th official, the match was temporarily suspended. After consultation with both teams, it was agreed that the match would restart with a different 4th official.

“Uefa will thoroughly investigate the matter and further communication will be made in due course.”