Newport Gwent Dragons captain T Rhys Thomas has been cited for allegedly biting an opponent during their European Challenge Cup win over Castres on Friday.
The 33-year-old faces a charge of allegedly biting Castres flanker Thomas Caballero in the second half of their 31-18 win on Friday.
If guilty, Thomas could face a ban of between 12 and 208 weeks.
His hearing will be held on London on Wednesday, 20 January.
Dragons are top off Pool 5 and assured of a quarter-final place going into their final group stage game at Sale on Thursday.
Thomas has won 27 Wales caps, the last against South Africa in 2008.