Uruguay forward Luis Suarez may be hit with lengthy suspension after Italy defender Giorgio Chiellini accused him of biting during the South Americans' 1-0 Group D victory at the World Cup on Tuesday.
FIFA have opened disciplinary proceedings against Suarez who escaped punishment during the match, Reuters reports.
"FIFA can confirm that disciplinary proceedings have been opened against the player Luis Suarez of Uruguay," the world soccer body said in a statement late on Tuesday.
FIFA said Suarez and the Uruguayan soccer association had until 5pm Brasilia time (20:00 GMT) on Wednesday to "provide their position and any documentary evidence they deem relevant".
FIFA is probing what it called an apparent breach of two articles of the organisation's disciplinary code. One covers infringements and the other offensive behavior and fair play.
Suarez and Chiellini clashed in the Italian penalty area 10 minutes from the end of the match which sealed Uruguay's progression and Italy's elimination from the tournament.
Chiellini furiously pulled open his shirt to show the mark to the referee.
Photographs show what appeared to be bite marks on his shoulder and pictures also showed Suarez sitting on the ground holding his teeth immediately after the incident.
The Italians were still complaining about it when Uruguay's Diego Godin scored with an 81st-minute header to secure the win.
Uruguay coach Oscar Tabarez said he did not see the incident, and complained that the forward was being persecuted.
Liverpool's Suarez was banned for 10 games last year after biting Chelsea's Branislav Ivanovic in a Premier League match. In 2010, he was suspended for seven games for biting PSV Eindhoven's Otman Bakkal while playing for Ajax Amsterdam.
