Update: Bob Simon's 60 Minutes report"The Pink Panther"aired on March 23, 2014.

They've hit the most expensive jewelry stores in the best cities in the world. Their methods are audacious and precise. Using expert planning and military discipline a loose group of European thieves have stolen $500 million in valuables over 20 years. Most of the armed robberies have been of high-end jewelry such as diamonds and watches, but 60 Minutes has confirmed Europe's biggest art robbery ever, worth $163 million, was perpetrated by the group police have dubbed the "Pink Panthers." Bob Simon reports on the brazen thieves the authorities say are so expert, they are almost impossible to catch, on 60 Minutes, Sunday, March 23 at 7 p.m. ET/PT.

They are called Pink Panthers after a 2003 London Graff jewelry heist, when they hid a gem in a jar of cold cream, a scenario straight out of one of the Pink Panther film comedies. Ron Noble, secretary general of Interpol, calls them the most notorious group of criminals he's ever investigated. "The problem is that they've become legendary because they are so good in their planning and their execution of robberies," he tells Simon. They learned their trademark discipline and planning in the Bosnian Wars says Noble. "Paramilitary training. Very organized, very disciplined and ruthless. And [they] were the ones who started it back in '94, '95, '96," Noble says of the founders, many ex-Yugoslavs who fought in the Serbian special forces.

Now there is a second generation of Panthers who utilize their connections to the Balkan communities in various countries to stage robberies, finding the experts and supplies they need. Many of their robberies involve an attractive, well-dressed woman who presents herself as a customer to the luxury shop, while secretly doing surveillance. After she leaves, a team of men appear, sometimes wearing disguises, and brandishing guns or in some cases, pepper spray - they are the "smash and grab" team. They are known for their speed, taking as little as 30 seconds before they are in and out. They make speedy getaways, too. In Dubai, they drove cars right into a mall and into the high-end jewelry shop. In Geneva, they used motorcycles to race down streets too narrow for police cars. In San Tropez, where traffic is legend, they escaped by speedboat.

Interpol says they have identified 800 Pink Panthers from photos, fingerprints or DNA. Their use of multiple fake identities to travel with, and the gang's loose structure, makes them hard to catch. They like jewelry, like $30 million necklaces and expensive watches, which are easy to carry and conceal but can add up to millions when fenced. Art is a new and more difficult quarry. 60 Minutes has confirmed masked Pink Panthers in 2008 used guns and a slick getaway to steal priceless paintings from a Zurich museum. The priceless loot - including a Cezanne, a Monet, a Degas and a van Gogh --- was worth $163 million. It was the largest art robbery in European history.

The art was eventually recovered, the last painting in Serbia. Diamonds are another story. Small diamonds are not identifiable, and even large diamonds with laser markings can be recut and made untraceable for resale in the world's diamond capital, Antwerp, Belgium. Diamonds may be the Pink Panthers' best friends. Patrick Peys, chief inspector of Antwerp's Diamond Squad, acknowledges it's hard to find stolen diamonds in a city with thousands of diamond dealers, where billions of dollars in diamonds are traded every day. It's an advantage the criminals have in addition to their speed. "I wouldn't advise anybody to start that career, but yes, I can imagine that from their view that, yeah, it's a living," he tells Simon. "And the possibilities of getting caught are probably not that high."