Inter boss Leonardo has asked Gennaro Gattuso for an explanation after the Milan man sang a derogatory chant about him during the Scudetto celebrations.
Following the 0-0 draw with Roma which clinched the Scudetto, Gattuso joined in with a section of the Milan fans as they chanted against the former Rossoneri boss.
The incident hasn't been lost on Leonardo, a man who joined Inter in December, and he's gone as far as making a statement on the Inter website.
"The day I decided to leave Milan, Gattuso said to me that I had at least been coherent in my choice," the note from the Nerazzurri boss states.
"But today I read in lots of papers that he still wants to give his own version of events.
"I would very much like to know what he has to say, since neither on the phone nor in person has that ever been possible.
"Furthermore, I would like to know what Milan's official position is on this matter."
Leonardo and Gattuso had a difficult relationship while the Brazilian was in charge of the Diavolo last season.
"Leonardo is upset about this," Inter President Massimo Moratti stated when questioned on the subject.
"The incident speaks for itself. It's something that is not representative of Milan, but of the man even if I think something needs to be done.
"There's no polemic, these things happen in moments of excessive celebrations. It's normal, because it has been a long time since they've had such a party."
Milan Vice-President Adriano Galliani is eager to play down the situation. "Let's not make a drama out of this," he said. "I haven't seen the footage but I think it is just a venial sin."
Watch Serie A live in the UK on Premier Sports for just £11.99 per month including live LaLiga, Eredivisie, Scottish Cup Football and more. Visit: https://subscribe.premiersports.tv/