Fifa said it has opened a disciplinary probe against Luis Suarez of Uruguay for allegedly biting an Italian opponent during a World Cup game on Tuesday.
Uruguay won the game 1-0 but it was overshadowed by the incident involving Suarez and Italy's Giorgio Chiellini.
Suarez has already banned twice before in his career for biting opponents.
The latest incident happened moments before a teammate scored the winner for Uruguay, who now advance to the next round of the tournament.
Fifa rules mean that Suarez, who plays his club football in England with Liverpool, runs the risk of a heavy punishment that could bar him from the rest of the World Cup in Brazil, just as Uruguay emerged from the group phase and reached the round of 16.
Watch: Biting incident mars Uruguay World Cup win