UEFA is to study videos appearing to show Celtic supporters participating in sectarian chanting in their recent Champions League game against Barcelona.
A Uefa spokesman confirmed the footage included singing outside and inside the Nou Camp for the match on 4 March.
“We have received some footage showing Celtic supporters singing some alleged anti-Queen and pro-IRA songs – sectarian songs,” he said.
“If the investigation is conclusive, a disciplinary case would be opened.
“We take care of all manifestations of sectarian singing.
“The only condition is that it must be in the immediate surrounding area of the stadium. There was alleged sectarian singing inside the stadium.
“It will depend on the easiness of having these songs understood and the quest of finding other evidence.”