Dylan Hartley has been cited for apparently biting an opponent during England's 30-9Six Nations win over Ireland on Saturday.
The Northampton hooker allegedly bit the finger of Ireland flanker Stephen Ferris and could now face being banned from international rugby.
International Rugby Board's disciplinary sanctions suggest that Hartley could be suspended for anything in between 12 weeks and four years.
In a statement, the Six Nations said: "England hooker Dylan Hartley has been cited following the RBS 6 Nations match between England and Ireland at Twickenham on Saturday for an alleged biting offence.
"The player's hearing will be held by an independent Six Nations disciplinary committee at a date to be confirmed."
Hartley has been capped 39 times by England since his debut in 2008.
