The fourth official at the centre of the walk-out protest staged by Paris Saint-Germain and Istanbul Basaksehir on Tuesday night is facing at least a 10-match ban if found guilty of using racist language by a UEFA disciplinary investigation.
Romanian official Sebastian Coltescu was accused of using alleged racist language towards Basaksehir assistant manager Pierre Webo in an incident which halted the Champions League game and led to the fixture being postponed to Wednesday.
Article 14 of UEFA's latest edition of discipline measures and procedures states that "any person under the scope of Article 3 who insults the human dignity of a person or group of persons on whatever grounds, including skin colour, race, religion, ethnic origin, gender or sexual orientation, incurs a suspension lasting at least 10 matches or a specified period of time, or any other appropriate sanction."
Article 3 states that all match officials are subject to article 14 rules, as well as all clubs and their officials, all players and all UEFA officials.
If found guilty, Coltescu would therefore miss a minimum of 10 matches in European competitions, or any other punishment which UEFA deems appropriate.
On Wednesday, UEFA appointed an Ethics and Disciplinary Inspector "to conduct a disciplinary investigation regarding the incident and the events that led" to the game at the Parc des Princes being abandoned.
"Information in regards to this investigation will be made available in due course," a UEFA statement said.
Romanian Football Federation President Razvan Burleanu told Sky Sports News: "The words all of us have heard have no place in football, especially since the referees are representing the standard for respect on the pitch and for the abidance by rules.
"As a Federation, we are not only respecting the UEFA values regarding social inclusion, antiracism, and the eradication of hate speech, we are promoting these values. If it will be proved that it was racism, there will not be any acceptance from my side.
"We need to wait for all the details of this incident and the results of the investigation to draw conclusions. I believe it is obvious that the intention was not to offend anyone."
The Group H game, which is set to resume at 17.55 GMT on Wednesday from the 14th minute, will be officiated by a wholly new refereeing team led by Dutch referee Danny Makkelie.
Istanbul Basaksehir confirmed on Wednesday that the red card shown to Webo has been rescinded and he will be able to take place in the dugout as normal.
What is expected of UEFA officials?
Sky Sports News reporter Geraint Hughes...
UEFA and in particular their officials are under the spotlight as Sebastian Coltescu's alleged behaviour is now the subject of a thorough investigation by his employers.
It's not simple to become a UEFA official. As you would expect the men and women selected from National Associations across the continent are the best of the best.
UEFA give them the tools to their job. There are two conference meetings a year, one in winter and one prior to a start of a season, while ongoing dialogue flows between UEFA's refereeing hierarchy and the officials.
While a comprehensive understanding of the laws of the game, interpretation and implementation for officials is clear from reading through various UEFA publications, along with a Code of Conduct which focuses on betting and match-fixing, you have to delve into UEFA's General Terms and Conditions to find out a little more.
While not specifically referencing language, cultural sensitivities or race, the behaviour expected of a UEFA official is clear.
UEFA say that match officials "must refrain from any action whatsoever which could be of an unsporting nature and/or contrary to UEFA's interests", and that they must "behave in a professional and appropriate manner before, during and after any UEFA match for which they have been appointed."
The Conditions also state that "match officials undertake to apply and respect the Laws of the Game published by FIFA as well as UEFA's Statutes, regulations, directives, decisions, instructions and circular letters," with UEFA also adding that "any breach by match officials and/or national associations of these General Terms and Conditions or of the UEFA's Statutes, regulations, directives, decisions, instructions or circulars letters could result in proceedings being opened by UEFA's disciplinary bodies."
UEFA have long stated they have a zero-tolerance stance to racism. Current FIFA President Gianni Infantino said so when he was UEFA General Secretary, while current UEFA President Aleksander Ceferin, one month after being elected to UEFA's top job in 2016, said "racism, discrimination and intolerance have no place in football... I believe strongly that we must stand up to racism and all forms of discrimination, and I am proud of the work done by UEFA and our partners in tackling these issues."
Jose: Walk-off iconic in fight against racism
Jose Mourinho believes Paris Saint-Germain and Istanbul Basaksehir players walking off and their Champions League match being postponed because of an alleged racist incident could be an "iconic" moment in the fight against racism.
"It's a very sad situation and every form of racism has to be fought. It's never accepted. I'm very sad because we don't want that in football," said the Tottenham head coach.
"I personally know the referee, Ovidiu Hategan. Good guy, very good referee. To be involved indirectly in a game that will become quite iconic is not a nice thing.
"The fourth official, only he can express his feelings. Of course he made an unacceptable mistake but only he can open his heart, apologise and accept the consequences. Probably he is a very good referee.
"Everyone in football and society, we have our responsibilities in relation to these situations and if we make mistakes, we have to accept the responsibilities.
"But more important for me is that that game becomes quite iconic. Champions League, to stop after 15 minutes for a very sad reason, will become iconic and hopefully, in the future, never happens again."