Gabriele Sandri's death has angered many in Italy

Police had said Sunday's shooting of Gabriele Sandri, 26, by the officer was a "tragic accident".

There had been expectations he could face a manslaughter case but the policeman's lawyer said on Thursday a murder charge was being prepared.

Mr Sandri's death sparked widespread fan riots across Italy which left 40 policemen injured.

Mr Sandri, a disc jockey, was hit by a bullet in the neck in the Tuscan city of Arezzo as he sat in a car while police tried to stop fighting between Lazio and Juventus followers.

'Unforgivable act'

The policeman, named in the Italian media as Luigi Spaccarotella, has said his gun went off as he ran to stop a brawl between rival supporters.

He told the newspaper Corriere della Sera earlier this week that he fired his pistol by accident more than 200m (660ft) away from Mr Sandri.

His lawyer Francesco Molino vowed to robustly defend any criminal charges.

But chief prosecutor of the Arezzo jurisdiction Ennio Di Cicco was quoted by La Gazzetta dello Sporto as saying: "This traffic policeman fired the shot at the height of a human being, that is a certified fact.

"We don't know the motives but whatever they are it's an unforgivable act."

The latest development came a day after hundreds of people, including rival fans, attended the funeral of Mr Sandri in Rome.

In April, the government introduced a law designed to stamp out football hooliganism following the death of a policeman in rioting at a match in Sicily in February.