Poznan - Mario Balotelli was racially abused during Italy's 1-1 Euro 2012 Group C with Croatia at the Municipal Stadium in Poznan, Poland, an AFP photographer at the game said.
The photographer was situated in the corner where the majority of Croatian fans were sitting during Thursday's match and said he heard monkey noises being directed at Balotelli.
At one point he also saw a steward picking up a banana that had been thrown onto the pitch.
There was no immediate comment from UEFA, who said only that they were awaiting the referee's report from the match.
On Tuesday UEFA said it was invesigating claims Balotelli, who is of Ghanaian origin, was racially abused during Italy's 1-1 draw with Spain in Gdansk on Sunday as well as a similar incident in the Russia-Czech Republic match in Wroclaw last Friday when Czech full-back Theodor Gebre Salassie was also allegedly targetted.
Italy coach Cesare Prandelli, though, had strongly rejected the claims that Balotelli was abused against Spain.
"That's absolutely untrue," the Azzurri coach said at a news conference on Monday.
Manchester City forward Balotelli, 21, has said that he would walk off the pitch if he were racially abused by fans.
Although UEFA has said it has opened an inquiry into the claims against Balotelli and Gebre Selassie, it has not started any proceedings.
Racism at stadiums in the two host nations Poland and Ukraine was thrown into the spotlight following a BBC documentary that showed footage of fans giving Nazi salutes, making monkey noises and at one point attacking a group of Asian students.
Dutch players also claimed they heard racist chanting during training in Krakow before the tournament even began.