The Fascist salute is a crime - but only in certain circumstances - Italy's top court has ruled, with experts warning convictions are unlikely just days after a video of a mass salute caused outrage.

The Supreme Court made its decision Thursday in a separate case of eight people convicted for raising their right arms in what is also known as the Roman salute during a ceremony in Milan in 2016.

It came just days after around 1,000 people were filmed saluting at the former Rome headquarters of the Italian Social Movement (MSI), a party formed by supporters of Fascist dictator Benito Mussolini after World War II.

The images went viral, sparking calls for prosecutions from opposition politicians - but also revealed confusion over whether the salute was illegal.

Prime Minister Giorgia Meloni has been criticised for refusing to condemn the event.

Her far-right Brothers of Italy party has its roots in the MSI - and she joined its youth wing at 15.

The Supreme Court judges concluded that the Fascist salute and the roll call ceremony - whereby participants at a demonstration reply "Present" while raising their arms, as they did in Rome on January 7 - are offences.

The judges said the rituals were "evocative of the gestures typical of the dissolved Fascist party" of Mussolini, who ruled Italy with an iron fist between 1922 and 1943.

But they added that a crime is not committed under the anti-Fascist Scelba law of 1952 if the gestures are carried out during a commemoration, and if it cannot be proven that those involved have the intentions of reviving the Fascist party.

The judges also said another law, the 1993 Mancino law, which sanctions acts of discrimination or violence of a racial character, could be used. But the courts must decide.

In the Milan case, the Supreme Court granted the defendants the right to appeal their convictions, saying the courts must decide whether there was a "concrete danger of reorganisation of the dissolved Fascist party".

A defence lawyer in the case, Domenico Di Tullio, welcomed the ruling, saying it proved that the Fascist salute was "not a crime" unless there was a real danger of reviving the Fascist party, or racial discrimination or violence.

"In Italy, opinions are not punished," he said.

Neo-fascist group CasaPound -- whose members are under investigation for the January 7 salutes -- also hailed it as a "historic victory".

'Complicated to prosecute'

But Emilio Ricci of the anti-fascist National Association of Italian Partisans (ANPI) said rather than being ambiguous, the ruling clarifies how neo-fascists can be prosecuted.

He called on authorities to charge the participants of the January 7 event, held in memory of the 1978 murders of two teenage activists of the MSI youth wing.

Their killings were blamed on left-wing militants but nobody was ever convicted of the crimes, which came during a period of political violence in Italy known as the "Years of Lead".

"I hope the prosecutors will indict them for violation of the Scelba and Mancino laws," Ricci said.

Constitutional expert Gaetano Azzariti told AFP the Supreme Court "confirmed the anti-fascist values" of the post-war Italian republic.

With Thursday's ruling, it upholds the crime of apology for fascism, while leaving the application to the courts -- a balanced approach, in his view.

But Giulio Vigevani, a professor of constitutional law, said it would still be complicated to prosecute the Fascist salute.

"The salute in itself is not a crime, it only becomes a crime if the rite qualifies as a danger of reorganisation of the Fascist party," he told AFP.

"In 99 per cent of cases, it will be no" to prosecution, he said.

"The constitution says that Italian democracy is open, it is not afraid of its enemies."

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.