UEFA is awaiting reports from the referee and match delegate before deciding their next move following the racist abuse directed at England players in Sofia on Monday.
Gareth Southgate's side beat Bulgaria 6-0 in Euro 2020 qualifying but the match was overshadowed by monkey chants and Nazi salutes from home supporters at the Vasil Levski National Stadium.
The incidents prompted the match to be halted twice in the first half - following UEFA protocol for tackling incidents of abuse at games - with a third meaning the game would have been abandoned.
Omnisport understands the Control, Ethics and Disciplinary (CEDB) arm of European football's governing body will now assess reports from the match official Ivan Bebek as well as the match delegate, who will also receive information provided by spotters from anti-racism group FARE.
The CEDB can also take reports from other sources, including the Football Association (FA), which has already called for an investigation "as a matter of urgency".
An FA statement read: "We can confirm that England players were subjected to abhorrent racist chanting while playing in the Euro 2020 qualifier against Bulgaria.
"This is unacceptable at any level of the game and our immediate focus is supporting the players and staff involved.
"As we are sadly aware, this is not the first time our players have been subjected to this level of abuse and there is no place for this kind of behaviour in society, let alone in football.
"We will be asking UEFA to investigate as a matter of urgency."
We can confirm that @England players were subjected to abhorrent racist chanting while playing in the #EURO2020 qualifier against Bulgaria.
— The FA (@FA) October 14, 2019
This is unacceptable at any level of the game and our immediate focus is supporting the players and staff involved.
Bulgaria coach Krasimir Balakov claimed not to have heard the chanting and accused the England supporters of "unacceptable" behaviour.
He told ITV Sport: "I personally did not hear the chanting that you are most probably referring to. I saw that the referee stopped the game.
"But I also have to say that the unacceptable behaviour was not only on behalf of the Bulgaria fans but also the English fans, who were whistling and shouting during the Bulgarian national anthem.
"During the second half they used words against our fans, which I find unacceptable."
