UEFA president Michel Platini on Monday condemned Croatia fans who racially abused Italy's Mario Balotelli and said he had travelled to the Balkan country last year to warn the authorities there about the problem.
"I'm not happy for Croatia. I was in Croatia a year ago and I'm not happy. They have a good team which plays well but it's unacceptable when you've got a hundred or so a*******s among the crowd," he told reporters in Warsaw.
Croatia's football federation are facing a possible stiff penalty after a UEFA-baced racism monitoring group reported that up to 500 Croatia fans taunted Balotelli throughout their Euro 2012 Group C match last Thursday.
An AFP photographer positioned in front of the fans at the stadium in Poznan, western Poland, also reported seeing a steward picking up a banana from the pitch.
Platini said that during his trip to Croatia, the country's football authorities were warned about the possibility of racist fans at Euro 2012.
"They (the Croatian federation) knew (that it could happen)," he added.
"Any form of racism is a problem. One case is too many."
The case is the first for racism at Euro 2012, which is being held in Poland and Ukraine, and will be eyed closely given Platini's previous assertions that European football's governing body has a "zero tolerance" on the issue.
The disciplinary committee is expected to give its ruling on Tuesday.