THE whistles around the San Paolo grew shrill when the helicopter flew over for a second time.

Although the stadium was less than half full because of a ban imposed on the more raucous fans, the police pilot would have heard the derision above the sound of the rotor blades. So could the hundreds of officers outside, marshalling protesters circling the ground with their banners — “We are the true Napoli” — watched by stall-holders selling scarves that say “Roma Merda” and other bits of anti-establishment paraphernalia.

This was the atmosphere at Napoli against Palermo, two of the more muscular cities from the Italian south. Napoli’s victory propelled them into the top four of Serie A. For a club that has known dramatic plunges — a spell in Serie C — and rises in the past decade, to declare a Napoli revival would be pre-emptive, but there is an optimism that a place in next season’s Champions League is a realistic target.

The more vivid discussions, though, surround the bans on fans. Both ends of San Paolo are currently closed, with away support heavily restricted. Those who cheer on Napoli in Genoa today will have slipped through a blanket ban on supporters travelling north for the game.

The reason is the events of August 31, when some 2,000 Napoli fans arrived in the capital for the Serie A opener in the Stadio Olimpico against AS Roma. Trains had been vandalised on the way. The lead-up to the match and the 1-1 draw were marred by fighting, with various missiles thrown. The Napoli supporters argue there was an aggressive posture throughout from the police. A “zero-tolerance’ attitude to policing of football followers in Italy has been adopted since the death of a carabiniere during rioting at the Sicily derby between Catania and Palermo last year.

After the Rome violence, police released figures stating that more than 800 of those who travelled from Naples to the match had criminal records and that 27 were connected to the Camorra, the city’s notorious organised crime network. Franco Roberti, the anti-mafia investigator , has since publicly detailed the principal areas of overlap, “the subtle link”, he called it, between the Camorra and the ultras of Napoli.

He drew attention to the numbers of fans prosecuted or charged in connection with drug-trafficking — more than 200, Roberti claimed — and described clan battles that had been settled in the San Paolo. He also talked of direct recruitment by the Camorra among groups of ultras and recalled the influence of organised crime on Napoli’s fortunes during the club’s most glorious high-profile era, the late 1980s.

The face of that period is everywhere around the San Paolo, on scarves, shirts, flags and ornate graffiti. It is Diego Maradona, who arrived in Naples in 1984 and saw a journalist bundled out of his introductory press conference for asking if he knew the money for his transfer from Barcelona had been provided by the Camorra. After inspiring the club to two league titles, Maradona embarked on his downward spiral. “In the 1980s, certain players were provided with cocaine by the Camorra,” noted Roberti.

If Maradona remains the most visible badge of honour for Napoli supporters, they now have another. For the opening home game of the campaign, many of those kept out of the ground by the closure of the areas behind the goals turned up to protest in shirts displaying the words “I’ve got a criminal past”.