Leinster Rugby has urged people to remember the singing, roaring and cheering of fans at Saturday's encounter against Ulster at the Aviva stadium rather than an "isolated" sectarian incident.
In a statement on its Twitter account on Sunday, Leinster said it was “aware of an isolated incident during yesterday’s game which was dealt with at the time by stewards and by gardaí.
“There is no place in sport or in our society for any form of physical or verbal abuse”.
One fan was reportedly removed from the ground after allegedly shouting sectarian abuse.
In a later tweet the club said: “Thank you to the vast majority of the 51,700 who sang, roared, cheered and urged both teams on in what was a hugely special day for Irish rugby.
“Let that be the narrative.”
Leinster beat Ulster in the game, 21-18, securing a place in the semi-final of the Champion’s Cup.