NICE, FRANCE // Even on rough-and-ready first estimates, the latest brazen diamond heist in the glamorous French resort of Cannes produced a haul worth about the same as the fabulous London residence of the jewellery's owner, Lev Leviev.

For once, the media were being unduly cautious. Next day, a presenter on French radio was talking in excited tones about the hold-up of the century.

Overnight, the value placed on the proceeds of the theft from Leviev's Extraordinary Diamonds summer exhibition at the luxury Carlton Hotel had leapt from €34 million (Dh191 million) to €103m. This figure, given by the public prosecutor's office in Nice, rivals a 2003 raid at the diamond centre in Belgium's gems capital, Antwerp, as the most lucrative in history.

The robbery has already been linked, in media reports, to the Pink Panthers, an energetic band of jewel thieves whose members have included hardened veterans of civil war in the former Yugoslavia.

It was executed in a slick but hardly sophisticated operation by a solitary gunman dressed in dark clothes and brandishing an automatic pistol.

He slipped past security guards to enter a first-floor suite at the hotel, a setting for the classic Alfred Hitchcock crime thriller To Catch a Thief, through half-opened French windows that should have been closed.

In the Oscar-winning 1955 film, Cary Grant starred opposite Grace Kelly as a reformed cat burglar who sets out to capture another crook stealing jewels from wealthy visitors to hotels and villas along the Côte d'Azur.

Reform is unlikely to have been on the mind of the Carlton gunman as he intercepted the transfer of Leviev diamond earrings and other valuables from a safe to display. His crime was completed in about a minute just before noon before he disappeared into the crowds on the famous Cannes promenade, the Croisette.

Once again, for however long it may take before any of the proceeds are recovered or criminal charges brought, the international jewel thief had triumphed over authority.

"Bravo," wrote one of several French online news-site contributors to reveal a hint of admiration for the perpetrator. "Done without hatred, without violence."

The world, it seems, holds a sneaking regard for the thief who uses guile but little or no actual violence to relieve the super-rich of a portion of their belongings.

Police and prosecutors discourage the notion of victimless crime, pointing out that a man with a gun is a man who might fire it. But, on the lips of more than one man on the boulevard, there is more appreciation of the robber's flair than sympathy for the robbed.

Mr Leviev, an Israeli of Uzbekistan origin who turned 57 two days after the theft, was estimated by Forbes this year to be worth US$1.5 billion (Dh5.5bn). His company is one of the world's leading diamond manufacturers and has boutiques in Dubai, London, New York and Singapore.

Perhaps on the Riviera, news of the small dent in Mr Leviev's fortune brought entertaining relief after stories of delinquent behaviour on beaches by thuggishly antisocial young men from the tough banlieues, the edge-of-city housing estates of Paris and elsewhere.

But the appeal of the suave robber has international reach.

French popular fiction has its own prolific gentleman thief, Arsène Lupin, but the theme appears in other cultures, too, as shown by Lupin's British equivalent and contemporary, AJ Raffles.

For their part the Pink Panthers attract respectful comment in their native Balkans.

A Los Angeles Times report in 2009 quoted Dragan Ilic, a Belgrade radio talk-show host: "They've become more than pure criminals, they're heroes. They're violent but they haven't killed anyone. It's as if they're saying, 'we can beat the technologically superior West with our raw power and intelligence.' They're feeding the western myth of the dark, tribal Balkans - these criminals coming from those wars and woods."

The details of Sunday's heist might have been scripted in Hollywood. Security and sales staff were coolly ordered to lie on the floor while the thief filled his briefcase. He then nipped smartly out into a side street through a conveniently open window, pausing to scoop up gems he spilt on his way.

It was the third major jewellery theft in or near Cannes since May, the others occurring with a few days of each other during the film festival.

In the first, Chopard jewels worth more than $1m, intended to be worn by stars on the red carpet, were stolen from an American executive of the jewellery house's Novotel hotel suite. Then a $2.6m De Grisogono necklace disappeared during a festival party at the five-star Hotel du Cap-Eden-Roc in Antibes.

The Riviera has long proved a productive hunting ground for the Panthers or their imitators. In 2005, five members took 75 seconds to steal jewels worth $2.65m from a Saint-Tropez boutique, making their getaway by speedboat.

After Sunday's much grander heist, speculation instantly settled on competing theories suggesting an inside job with the robber having some kind of assistance among hotel or jewel-house staff, an insurance scam and, inevitably, the possible involvement of the Pink Panthers. Nice-Matin newspaper quoted a source close to the inquiry as doubting insurance as a motive because the cover taken out on the gems was no more than half their value.

As for insider help, luxury hotel staff and security guards employed to protect high-value property know it is an occupational hazard that they will fall under suspicion when crime occurs. Hotel management said little about any aspect of the robbery but did insist that no employee was implicated.

With or without such help, the Pink Panthers - named after the movie featuring Peter Sellers as the incompetent French detective Inspector Clouseau and David Niven as "The Phantom", a playboy criminal - fit the media identikit for major jewellery robberies like a glove.

More a loose network of criminals than a single, tight gang of crooks, they originated in Montenegro and Serbia but expanded after Yugoslavia's disintegration to draw members from Bosnia and other new states.

They command a formidable and perhaps exaggerated reputation for spectacular robberies. Some estimates put the proceeds of their crimes at more than $500m from 150 raids in as many as 35 countries, the methods varying from the walk-in hold-up on Sunday to the smash-and-grab raid in Dubai in 2007. In the latter, robbers used two Audi A8 limousines to ram the glass facade of Wafi City mall and grab watches and valuables valued at Dh15m from Graff Diamonds.

The temptation to speculate on a possible link to Sunday's robbery, already powerful, became irresistible against a background of jail escapes by members imprisoned in Switzerland.

In the most recent breakout, last Thursday, Milan Poparic, 34, got away from a prison at Orbe, just 15 kilometres from the French border. With a Swiss kidnapper, Poparic - serving a six-year term for another jewel robbery - escaped as accomplices broke through a perimeter fence and fired Kalashnikov rifles to deter guards.

He was the third Pink Panther suspect to escape in as many months.

It may seem difficult to believe Poparic would be able to resume his criminal exploits within three days. But some observers saw clear similarities with Pink Panther operations of the past.

"The brazen drama of it is their style," Jonathan Sazonoff, US editor of the Museum Security Network website, said. "The theft of high-value diamonds is exactly what they do, so it's not a great leap to assume they are on the warpath again. They are a crime wave waiting to happen."

Why Cannes? "It's simple," he replied. "On the Cote d'Azur, it's where the moneyed people flow."

In a textbook display of locking the stable door only after horses have bolted, administrators in the Alpes-Maritimes department that includes Cannes announced on Tuesday that jewellers and designer boutiques along the Croisette would be urged to tighten security.

It came too late for Kronometry, a luxury jeweller on the Croissette, where two men sped away by motorcycle yesterday after entering the shop armed with handguns and a grenade and seizing several watches estimated to be worth at least €1m.