Ulster fans have been accused of racially abusing members of the Newport Gwent Dragons side during Friday's Magners Celtic League clash at Ravenhill.
According to a statement from the Dragons, a number of players were singled out for abuse by a minority of Ulster fans.
Some media reports have named Colin Charvis and Aled Brew as the players who were targetted.
The Welsh club said players had informed management of the issue at half-time in the game which Ulster went on to win 14-7.
The Dragons management had told Ulster officials of the issue on the night but are also planning on confirming in writing their concerns and disappointment over the incident.
"The Dragons realise that it was a small minority but feel the issue needs to be raised as is not acceptable in society and the game of rugby football," the club said in a statement.
This isn't the first time that Ulster fans have been embroiled in controversy with players from opposing teams.
Just last month, Toulouse players Gareth Thomas and Trevor Brennan clashed with Ulster fans during a Heineken Cup game.
Thomas is now serving a four-week suspension for making abusive gestures and attempting to enter the crowd at that match, while Brennan could face a life ban after allegedly assaulting a fan.
Brennan, who is due to retire at the end of the season, claimed that he had been provoked by taunts about his mother by opposing fans, leading him to leave the players enclosure and become involved in a fracas with an individual named as Patrick Bamford.
Bamford has since issued statements saying he is taking a civil action against Brennan as well as defamation actions against a number of media outlets.
Although it's Ulster fans that are currently in hot water over alleged racism, fans of the Dragons have also been accused of taunting visiting players in the past.
In April 2004, Glasgow Warriors claimed that their flanker Maama Mokitika was racially abused in a game at Rodney Parade.
The Warriors alleged that Mokitika had been taunted by Dragons fans after being dismissed in the 69th minute.
An internal inquiry by the Dragons rejected the claims.
