Disciplinary chiefs have launched an investigation into the ugly scenes which marred defending champions Saracens' 15-6 Heineken Champions Cup victory over Munster.
A prolonged mass brawl erupted at Allianz Park amid allegations that the Irish province's chief medic Dr Jamie Kearns had made a remark about England hooker Jamie George's weight.
European Professional Club Rugby announced on Sunday that it is looking into "incidents" during the match and would seek the views of referee Pascal Gauzere and his officials and both clubs.
A statement said: "EPCR has decided to investigate incidents which occurred during the second half of the Heineken Champions Cup, Round 4 match between Saracens and Munster Rugby at Allianz Park yesterday (Saturday, 14 December).
"Information will now be sought from the match officials and from both clubs and EPCR will be making no further comment until the investigation has been completed."
The brawl spread to the athletics track surrounding the pitch and then split into pockets of conflict before order was finally restored.
Saracens' assistant coach Alex Sanderson later claimed that it had been sparked by a comment from Dr Kearns about George.
Saracens were trailing 6-3 at the time, but hit back with tries from Sean Maitland and Mako Vunipola to keep themselves in the hunt for a place in the quarter-finals.