Toulouse player Trevor Brennan lashed out at an Ulster fanToulouse players Trevor Brennan and Gareth Thomas will both face misconduct charges arising from last Sunday's Heineken Cup clash against Ulster.
Brennan faces an ERC charge of assaulting Ulster supporter Patrick Bamford after leaving the playing area at the Stade Ernest Wallon.
Thomas is alleged to have engaged in "aggressive exchanges with spectators".
The Welsh international's hopes of playing in this year's Six Nations are threatened by any potential ban.
The charge levelled against Thomas says that he "aggressively attempted to enter one of the seating areas" and/or "made an offensive hand gesture towards spectators".
Brennan claimed he was provoked by chants about his mother but this has been "categorically" denied by Ulster supporter Bamford.
Former Ireland World Cup forward Brennan and ex-Wales captain Thomas must now attend disciplinary hearings following an initial investigation by European Rugby Cup disciplinary officer Roger O'Connor.
The ERC have also announced further investigation into the behaviour of a section of Ulster supporters, and Toulouse's alleged failure to control their players with regard to the incident.
Disciplinary hearings for Brennan and Thomas will be convened as soon as practicable.
Toulouse mounted a vigorous defence of Brennan but Ulster claimed Brennan had tarnished rugby with his actions.
Brennan appeared to punch Bamford several times leaving the 25-year-old accountant with a suspected fractured skull.