Inter Milan manager Roberto Mancini has accused Napoli boss Maurizio Sarri of using homophobic language towards him during a touchline altercation.
"In England, someone like him wouldn't even be allowed on the touchline," the ex-Manchester City boss told Rai Sport.
After the Coppa Italia tie, Sarri said: "Am I homophobic? That seems over the top. I was just irritable."
The Italian Football Federation (FIGC) has launched an investigation into Mancini's allegation.
Mancini, 51, also called his fellow Italian "a racist" without elaborating on why he had made the claim.
Warning - the section below contains language some readers may find offensive
Mancini claims Sarri shouted "poof" and another homophobic slur as Inter sealed a 2-0 quarter-final win on Tuesday.
The Inter boss was eventually sent to the stands as his side clinched a 2-0 win thanks to goals from Stevan Jovetic and Adem Ljajic.
"I went to find Sarri in the locker room and he apologised, but I want him to be ashamed of what he said," added Mancini.
"People like him cannot be in football. If not, it never gets better."
Sarri, 57, claimed not to remember the exact words he had used towards Mancini during what was only Napoli's second defeat since August, adding that he had "heard worse on a football pitch".
"These are things that should end on the field," Sarri told Rai Sport.
"I apologised to him, but I expect him to apologise, too. A fight on the pitch should end after 10 seconds.
"I was fired up and angry, so I'm not sure what I said. I will admit it wasn't the right tone to take.
"I was not discriminating against anyone. If I did indeed use those words, then I apologise to the gay community."
Fabrizio Marrazzo from Italian lesbian, gay, bisexual and transsexual rights group Gay Center told BBC World Service Sport Sarri "should lose his job".
He added: "We are very angry about this."
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