Italian Prime Minister Giorgia Meloni is suing Placebo singer Brian Molko for defamation after he called her a fascist and a racist during a gig in Turin last month, Italian media report.
Mr Molko launched his expletive-filled rant from the stage of the Sonic Park festival.
Prosecutors in Turin opened an investigation into Mr Molko soon after.
Ms Meloni has not commented publicly about the issue although the BBC has approached her team for a reaction.
Videos from the Placebo concert posted on social media show Mr Molko shouting an expletive about the prime minister followed by the words "fascist, racist" in Italian, to cheers from the audience.
A few days later, sources told Italian news agency Ansa that prosecutors in Turin had opened an investigation into the incident for "defamation of [public] institutions".
Ms Meloni is leader of the far-right Brothers of Italy party and heads Italy's most right-wing government since World War Two. She has filed defamation lawsuits in the past. Last year, she initiated legal action for aggravated criminal defamation against the editors of Domani newspaper.
Domani alleged Ms Meloni had tried to help an MP from her own party win a government contract to procure face masks during the Covid-19 pandemic.
Ms Meloni rejected the allegation and sought damages of €25,000 (£21,500) from the paper. The trial is set to start in July 2024.
She also filed a defamation lawsuit against Roberto Saviano, a journalist and the author of Gomorrah, for calling her a "bastard" during a TV interview in 2020 in which he denounced her for attacks on migrant rescue NGOs.
The trial has been adjourned until October. If found guilty, Mr Saviano could face up to three years in jail.
Under Italian law, some defamation cases can be criminal and carry a custodial sentence.