Scarlets are to investigate claims of racist chants and behaviour during their Champions Cup quarter-final win.
Following the Welsh region's 29-17 win over La Rochelle, claims of racist behaviour from fans were made online.
"An investigation will be undertaken to understand the full facts and background of the incident before commenting further," said Scarlets.
"We have a proud history of being a family club and events such as this are completely unacceptable."
The club added: "The vast majority of the 15,500 sell-out crowd at Parc y Scarlets for the European Rugby Champions Cup quarter-final enjoyed a wonderful family-friendly occasion."
Scarlets are into their first Champions Cup semi-final since 2007.
An European Professional Club Rugby spokesman said: "EPCR is working with Scarlets in order to establish the facts of the case reported from Friday's quarter-final and won't be making any further comment at this stage."
Scarlets coach Wayne Pivac said he did not hear anything, but is keen for the club to investigate the matter further.
"I didn't hear anything myself, but I wouldn't expect to where we sit," he said.
"As a club we take it very, very seriously. There is no place for it (racism) in society, let alone here at Parc Y Scarlets.
"So we were very disappointed to hear that and we will wait for the outcome of the enquiries going on at present.
"If anything is substantiated we would take a very dim view of it and act accordingly."