A group of Lazio fans began chanting anti-semitic slogans during Sunday's Serie A match against Lecce.
A group of the notoriously fascist 'Ultras' fans in the North End of the stadium starting chanting: "Giallorosso ebreo", which means Jewish red-and-yellows.
Although Lecce play in red and yellow, it is believed to be an accusation against Lazio's bitter city rivals Roma, who share the same nickname as Lecce.
The chants only came from the North End according to Ansa news agency and other fans around the largely empty ground didn't join in.
Lazio fans have long been seen as fascist-leaning in Italy which has a sorry record on racism in football.
However, racist chanting usually targets people of African descent, with Juventus particularly guilty in that respect in recent seasons.
The Romanian travelling community has also come in for abuse from time to time.
Earlier this season Lazio fans came in for criticism after unfurling a banner bearing Nazi slogans and symbols, ostentatiously in support of the club's German forward of Polish origins Miroslav Klose.
Klose himself reacted angrily to that banner back in October.