Building on his success, Saviano was co-writer of a film adaptation that won the Grand Prize at the Cannes Film Festival this year and is Italy’s entry for the Academy Awards.

But today, he lives like the fugitive gangsters whom he chronicled — enduring round-the-clock protection, changing hide-outs, avoiding daylight.

Last week, two unmarked police sedans with flashing blue lights stopped on a quiet hilltop street here. Three bodyguards with the smooth, tough air of Italian plainclothes police hurried out to escort the author into the offices of his publisher.

Saviano, a close-cropped 29-year-old, has the physique of an amateur welterweight boxer, a sport he has taken up to relieve stress. He alternates between steely determination and a brooding weariness. He has caused a commotion by saying he might leave Italy to escape the dangers and pressures of his vita blindata, or armoured life.

“Right now the most difficult task for me is not writing a new book, but reclaiming my life,” he said, slumped on a couch.

“I don’t have a home... I move constantly. My family lives in northern Italy. All the people I knew in the past have distanced themselves, my girlfriends, everybody, everybody, everybody.”

Anti-mafia investigators praise Saviano’s courage in trumpeting their struggle to the world.

“I admire him because he created a new genre that has greatly widened the audience,” said Antonio Laudati, a top Justice Ministry official who led major Camorra prosecutions in his native Naples. “This was an issue that primarily interested specialists, prosecutors, journalists. Saviano broke open a new front. He informed the man on the street. He turned our prosecution files into literature.”

The book has brought death threats, smear campaigns and even lawsuits by the Camorra and its allies. Last week, there were new rumblings. A longtime protected witness who was a kingpin of the Casalesi, as the gang from Saviano’s hometown, Casal di Principe, is known, reportedly told an investigator about talk of a plot to kill Saviano before Christmas.

During the interview at his publisher’s office, Saviano took a phone call from a friend in law enforcement — a disturbing update about a band of fugitives blamed for the machine-gun killings of six Africans in Castelvolturno; an apparent message over drug turf that caused the Government to dispatch 500 soldiers to the region.

“They have discovered that the hit team that is roving in the province of Campania has bought a detonator,” he said. “So all of us who have security details are concerned. Because bombs are used to attack security details. This is a group that wants to die.”

Amid headlines about the threats, Prime Minister Silvio Berlusconi and other public figures last week declared solidarity with Saviano and urged him to stay in Italy. The extent of the peril is not clear because the supposed tipster has retracted.

But anti-mafia officials have little doubt that Saviano remains in danger.

The title of the book alludes to the biblical city of sin, Gomorrah, cited in a denunciation of the mob by a crusading priest who was assassinated in 1994.

Despite his impassioned hatred for the gangsters, Saviano acknowledges that the success of Gomorrah and TV series such as The Sopranos shows that the underworld exerts a persistent hold on the popular imagination.

“In the book I deal with that fascination, because they have it. But I dismantle it. I explain the tricks they use to appear fascinating, the way they dress and so on... But in reality, it is a life of s—-. They are always shut inside their homes. They have the same women who they have to share because they do not trust anyone, so it’s not true that they are big playboys.”

Whatever the future holds, Saviano takes comfort from the courageous example of figures such as prosecutor Falcone and Salman Rushdie, the British author who has lived under a death threat issued by Iran’s fundamentalist regime in 1989.

“He told me, ‘Liberate yourself, because no one else is going to liberate you’.”