Manchester United forward Anthony Elanga was subjected to an alleged racist comment by an opponent while playing for Sweden Under-21s against Italy, the Swedish FA has said.
Sweden submitted an oral report to the match referee and delegate after the allegations by Elanga, 19.
The Italian Football Federation (FIGC) said it denies the allegations.
"No-one should have to be exposed to racism, it is completely unacceptable," said Sweden manager Claes Eriksson.
"We all stand behind and support Anthony in this."
On Thursday, Uefa said it was investigating the matter.
In a statement, the FIGC said: "In relation to what was reported by the Swedish Football Association on its website and taken up by some media, the FIGC denies in the most absolute way that a footballer of the Under-21 national team, during the Italy v Sweden match played yesterday in Monza, expressed racist offenses against an opponent, among other things which, as far as we know, was not noticed by the match officials or the Uefa delegate.
"Hoping that the competent bodies will promptly clarify the case, as emerges from the television images broadcast... in the 92nd minute, two Swedish players rejoice for a long time for the goal and are recalled by Italian footballers to resume the game quickly.
"We reiterate that no racist offence was pronounced before, at that time or subsequently and that the FIGC will protect its image and that of its players.
"At the same time, the FIGC reaffirms the constant commitment made by all Italian football and in particular by the national teams, through numerous initiatives, to combat racism and once again condemns any discriminatory insult or episode of violence."
The European Under-21 Championship qualifier finished 1-1 on Tuesday, with Sweden scoring a 92nd-minute equaliser.
Elanga has featured once for United this season, coming on as a substitute during the Carabao Cup defeat by West Ham in September.
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