An Italian comic who said Pope Benedict would be punished in hell for the church's treatment of homosexuals could be tried for dishonouring him, a jailable crime under a 1929 treaty with the Vatican, judicial sources said.

Sabina Guzzanti, one of Italy's most pungent political satirists, made the remarks before a cheering crowd of thousands gathered at Rome's Piazza Navona in July.

Her explicit comments were widely published by Italian media and posted on the Internet at: http://www.youtube.com/watch?v=WEoxYUooV6o

The church, at the time, expressed its "profound displeasure with the offensive words about the Holy Father".

A Rome prosecutor has decided the comments may go beyond satire and break a law protecting the honour and dignity of the leader of 1.1 billion Roman Catholics, under a treaty signed by fascist dictator Benito Mussolini, the judicial sources said.

After reviewing the case file, the prosecutor's office asked Justice Minister Angelino Alfano for permission to proceed against Guzzanti with an investigation that could end in a trial. No answer has yet been given.

"We're in the Middle Ages," Paolo Guzzanti, Sabina's father, a conservative senator allied with Prime Minister Silvio Berlusconi, told Italian media.

Leftist politicians said the issue was one of free-speech. Socialist Bobo Craxi warned that punishing satire would bring Italy close to a totalitarian state.

Among the Lateran Treaties that established Vatican City as a sovereign state within Italy, the "Cordatato" treaty provided that offences against the pontiff be punished the same way as offences against Italy's president.

They can be punished with five years in prison.

Guzzanti, famous for her criticisms and impersonations of media mogul Berlusconi, has long complained of media censorship. Her television show "Raiot" was taken off the air in 2003 after a defamation suit from Berlusconi's broadcaster Mediaset.

But Roberto Castelli, a former Berlusconi justice minister and now a cabinet aide, said Guzzanti had committed no crime.

"I don't agree with absolutely anything Sabina Guzzanti says, much less about the Pope, but I defend her right to say all of the enormous idiocies she wants," Castelli said.