Atletico Madrid have been charged by UEFA for displaying what European football's governing body described as a "racist" banner during the Europa League final.
Omnisport understands the charge relates to a flag displayed by fans inside Groupama Stadium that appeared to be styled like a Nazi war ensign.
UEFA has charged Atleti, who won the final against Marseille 3-0, with alleged racist behaviour and the setting off fireworks.
Disciplinary proceedings have also been opened against Marseille, with charges relating to alleged crowd disturbances, acts of damage, setting off of fireworks, throwing objects and for delaying the kick-off.
The case will be heard by UEFA's Control, Ethics and Disciplinary Body on May 31.