Rome - Gomorra is on its way to the Oscars as Italy's official candidate, but counterfeit DVD copies have already hit the streets of Naples - a market controlled by the local mafia whose dealings the film denounces.

"Why the surprise?" Naples anti-mafia, prosecutor Fausto Zuccarelli was quoted as saying by the daily, La Stampa, on Thursday.

He was referring to the Camorra's alleged involvement in distributing the film based on the best-selling book of the same name whose publication in 2006, so angered mob bosses, that they threatened to kill author Roberto Saviano.

An exasperated Saviano, who has been living under under a 24-hour police guard for the past two years, announced last month he was planning to leave Italy.

The book focuses mainly on the Casalesi, crime families based in Casal di Principe, near Naples, and they would probably want nothing to do with the illicit trade involving the film version, and the negative publicity it brings them, Zuccarelli said.

But this won't have stopped rival Camorristi from trying to profit off the film whose official DVD release in Italy is slated for December 3, the prosecutor said.

"I suspect the Neapolitan Camorra invests its capital in China where the pirate DVDs are produced and then exported abroad," Zuccarelli told La Stampa.

Naples is considered a world centre in the trade of fake and counterfeit goods, ranging from clothes to electronics, a situation which has prompted US authorities to call on Italy to tighten controls.

In recent years, police in the southern port city have seized millions of CDs and DVDs, many of which are believed to have been illegally manufactured in China.