A minority of Blues supporters stand accused of having sung anti-Semitic songs during a continental fixture in Hungary on December 13.
Premier League rivals Tottenham are said to have been the subject of the chants in the question.
Chelsea addressed the issue at the time, with the club branding the chanting “abhorrent” while conceding that those involved had “shamed the club”.
A statement released by the west London outfit read: “Antisemitism and any other kind of race-related or religious hatred is abhorrent to this club and the overwhelming majority of our fans. It has no place at Chelsea or in any of our communities.
"We have stated this loud and clear on many occasions from the owner, the board, coaches and players.
“Any individuals that can’t summon the brainpower to comprehend this simple message and are found to have shamed the club by using antisemitic or racist words or actions will face the strongest possible action from the club.”
UEFA has now revealed that it will be carrying out further investigations into the matter.
European football’s governing body have appointed an inspector to look into the alleged incidents due to a lack of evidence provided by officials at the game.
Chelsea have been informed that “disciplinary proceedings have been instigated”.
A charge of “racist behaviour” will now be judged at the next meeting of UEFA’s control, ethics and disciplinary body on February 28.
The full update issued on UEFA's official website read: “Based on the report submitted by the UEFA Ethics and Disciplinary Inspector commissioned to conduct an investigation - according to Article 31 (4) of the UEFA Disciplinary Regulations (DR) - in relation to the alleged racist incidents that occurred at the afore-mentioned match, UEFA has announced that disciplinary proceedings have been instigated against Chelsea FC in accordance with the Article 55 of the DR.”
Chelsea, who have made it through to the last 32 of this season’s Europa League, are due to return to continental competition on February 14 against Malmo.
That contest is due to take place in Sweden, with a return date at Stamford Bridge set to be staged a week later.