Napoli defender Juan Jesus on Monday blasted Francesco Acerbi for denying he dished out racist abuse after the Italy international was forced to leave the Azzurri's training camp ahead of two friendlies in the United States.

Jesus had initially played down the incident following Napoli's 1-1 draw at Inter Milan on Sunday, telling DAZN "what happens on the pitch, stays on the pitch" after accepting Acerbi's on-field apology for unspecified insults.

Brazilian Jesus, who headed home Napoli's late equaliser at the San Siro, had been seen protesting to match referee Federico La Penna, pointing to the Keep Racism Out badge on his shirt and apparently saying that "(Acerbi) called me a negro".

Acerbi left Italy's training camp after reports that he will be investigated for the alleged abuse, and was replaced by Roma centre-back Gianluca Mancini in the 28-man squad selected before matches against Venezuela and Ecuador in the build-up to Italy's European title defence.

He insisted on his return to Milan that he "didn't say anything racist", echoing what his agent Federico Pastorello had said to broadcaster Radio Sportiva earlier on Monday.

That sparked an angry reaction from Jesus on Instagram: "I thought that the incident was done with on the pitch and frankly I was hoping not to have to come back to something so despicable."

"However today I read Acerbi's comments which conflict completely with what happened, with what he himself said on the pitch which is backed up by video footage of him asking me for forgiveness," Jesus added.

"I'm not having it, racism is going to be fought here and now. Acerbi said to me 'get lost black, you're just a negro'... now he's changed tack and claims that there was no racism."

Jesus' reaction is bad news for Acerbi as Italian Football Federation (FIGC) regulations say that if he is found guilty of racially abusing the Brazilian he will be banned for at least 10 matches.

And authorities can ask for an even longer ban if they feel his behaviour warrants it.

A guilty verdict would be guaranteed to end his club season with Inter, who are set to win their 20th league title as they lead AC Milan by 14 points with nine fixtures remaining.

And disciplinary authorities will likely insist that any eventual ban be extended worldwide with the Euro starting on June 14.

Serie A told AFP that the regular report from the division's "sporting judge" Gerardo Mastrandrea will be released on Tuesday.

That document, which is usually published the day after the end of each round of matches, should confirm whether Acerbi will be investigated for the incident.

In a brief statement Inter said that they "will meet with the player as soon as possible to shed light on the exact details of what happened".