Ireland and Leinster flanker Seán O'Brien has been sanctioned by the IRFU following "an incident of inappropriate behaviour" last month.
The 32-year-old, who is set to join London Irish next season, "expressed his deep regret" over an incident in a Dublin bar as Leinster celebrated winning the Pro14 title for the second season in a row after beating Glasgow last month.
O'Brien has now apologised to the person involved and has been "sanctioned in line with the provisions of his contract" according to a statement released by the IRFU on Monday to the Irish Independent.
"The IRFU have investigated an incident of inappropriate behaviour by a player which occurred on 26th May 2019. The player has expressed his deep regret and has been sanctioned in line with the provisions of his contract.
"The player has apologised to the individual involved. The IRFU, and the player, regret any upset that this incident has caused."
The incident took place on the same night that ex-Leinster prop Stan Wright reportedly punched current academy player Jack Dunne, leaving the 20-year-old unconscious.
Meanwhile, Seán O'Brien has already been ruled out of this year's Rugby World Cup in Japan after undergoing surgery on his hip at the end of last season.
The Carlow native will not join up with the rest of Joe Schmidt's team in Asia and could have to wait until 2020 to make his debut for London Irish, with O'Brien expected to spend around six months on the sidelines.
The flanker signed a three-year deal with the Premiership club, putting an end to his ten years as a Leinster player and likely finishing his international career, considering the IRFU's policy of not selecting players who ply their trade abroad.