Former Manchester United star Lukaku appeared to be subjected to "monkey chants" as he prepared to take - and score - a match-winning penalty in Inter's 2-1 Serie A victory on September 1.

But Serie A's disciplinary body determined it was not admissible in the case and evidence from police was not deemed sufficient to punish the Sardinian club.

Moise Kean was subject to racist abuse when he played against Cagliari for Juventus last season, as was Blaise Matuidi the year before.

The Italian league did not sanction Cagliari for either incident, nor did they do so when Sulley Muntari was abused by the same team's fans in 2017.

After the Cagliari match, Lukaku urged action against racism in soccer.

The 26-year-old wrote on Instagram: "Football is a game to be enjoyed by everyone and we shouldn't accept any form of discrimination that will put our game in shame. I hope the football federations all over (the) world react strongly on all cases of discrimination."

Australian Associated Press