Champions Cup organisers have spoken with Ulster Rugby and Racing 92 about Simon Zebo's tweet in which he said he was the subject of unacceptable comments from some fans in the Kingspan Stadium crowd during yesterday's game.
The former Munster man tweeted after the game: "I hope my ears deceived me with some comments directed my way from the crowd. #NotOn Django wins in the end."
'Django' would appear to be a reference to the 2012 Quentin Tarantino movie about an African-American slave.
A statement released to RTÉ Sport read: "EPCR has not received a formal complaint from Racing 92 regarding any alleged case of verbal abuse of one of the club’s players during yesterday’s Heineken Champions Cup, Pool 4 match at the Kingspan Stadium.
"EPCR is in contact with both Ulster Rugby and Racing 92, and will be making no further comment at this point."
Ulster also release a statement on Sunday which read: "Ulster Rugby condemns all forms of abuse and will work with the relevant parties to robustly investigate any complaints received."
Zebo scored one of Racing's four tries as they secured two losing bonus points to stay top of Pool 4.
The 28-year-old was replaced at half-time.
BT Sport said that Racing said the decision was "tactical" but his leg was bandaged up during the first half.
A tough place to play but great effort from the boys,2 important points on the road 💪🏾— Simon Zebo (@SimonZebo) January 12, 2019
Also I hope my ears deceived me with some comments directed my way from the crowd #NotOn
Django wins in the end ✌🏾 pic.twitter.com/GAqrQ8W6HQ
The Cork native was involved in a controversial incident in the reverse fixture in Paris last October.
The winger prematurely celebrated a try and was advised by referee Nigel Owens to apologise to Michael Lowry, later giving the Ulster player his shirt and apologising again.
Zebo was booed by the crowd during yesterday's game.