The Italian Football Federation have confirmed they are opening an investigation into Romelu Lukaku and Zlatan Ibrahimovic following their spat in Tuesday’s Milan derby.

Lukaku and Ibrahimovic squared up to one another before half-time during Inter’s 2-1 win in the Coppa Italia quarter-finals, exchanging a series of insults in front of referee Paolo Valeri.

Both players were booked for the incident but the FIGC’s prosecutors have decided further punishment could be required.

“Federal prosecutor Giuseppe Chine has opened a case this morning relating to the verbal confrontation between Zlatan Ibrahimovic and Romelu Lukaku during Inter-AC Milan on January 26,” an official statement read, as quoted by FcInterNews.it.

“As part of the investigation, the federal prosecutor has decided to call upon referee Paolo Valeri, who in the next few hours will be asked to clarify the motivations for the sanctions he handed out to the two players during the match.”

As per Corriere della Sera’s print edition this morning, the audio and television footage will be acquired by FIGC prosecutors and analysed in a bid to find out exactly what was said between the two players.

It is not clear exactly how long the investigation into the incident will last, but it is not expected to take too long.

Lukaku and Ibrahimovic both face one-match bans already in the Coppa Italia, which the Belgian will serve in tomorrow’s semi-final first leg against Juventus.