Brian Molko launched into a rant in Italian about Ms Meloni, who leads the far-right Brothers of Italy party, on stage at the Sonic Park festival in Turin.

Speaking in front of around 5,000 fans, the frontman of the alternative rock band called the prime minister a "piece of s***" and described her as "fascist, racist".

His remarks prompted cheers from the audience.

Prosecutors in Turin officially opened an investigation into Molko for "contempt of the institutions" following the outburst.

He could be fined up to €5,000 (£4,300) if convicted.

Ms Meloni's lawyers have now taken legal action and filed a lawsuit for defamation, Italian news outlet La Stampa reported.

Meloni has filed other defamation lawsuits

The prime minister leads Italy's first far-right government since the end of the Second World War and is the first woman to hold the position of prime minister in the country.

She has already filed a defamation lawsuit against journalist Roberto Saviano, author of Gomorrah, who called her a "b******" during a TV interview in 2020 because of her anti-immigration policies.

She also filed a defamation lawsuit against the newspaper Domani after it accused her of helping an MP from her own party win a government contract to procure face masks during the pandemic.