As a growing number of the world’s wealthiest are looking for safe places to store their millions, many are turning to “investments of passion,” including famous works of art, rare collectibles and even wine.

Earlier this year, the sale of Edvard Munch’s “The Scream” for $120 million broke the record for the most expensive painting ever sold at auction. In 2011, the super-rich spent more than $11 billion on art and more than $5 billion on wine.

But where there’s big money being spent, there is also a big opportunity to rob the wealthy.

“The criminals follow the market and they follow the dollar. And as it moves around the world, that’s where they go,” said former FBI agent Robert Wittman.

(SLIDESHOW: The World's Biggest Art Heists)

Wittman was one of the first FBI agents to specialize in art crime. The FBI now has 14 special agents that are trained to recover high-value stolen cultural property.

Bonnie Magness Gardnier runs the unit and the National Stolen Art File, an online database of missing items with values ranging from $2,000 to tens of millions.

“We have about 7,600 items in the file right now,” Gardnier said. “We do have fine art, but we also have memorabilia things like Elvis’s school ring, documents, letters, pottery, sculptures, jewelry.”

Once stolen, the items move into the black market quickly. However, they do not often stay there.

“The person who stole that artwork knows it’s stolen. He goes to a dealer, antique shop, pawn shop, and turns it into cash,” Gardnier explains. “We don’t require here in the United States that the sale of a work of art have a title document to go with it.”

There are also plenty of buyers around the world who do not care where the collectibles come from. CNBC wealth reporter Robert Frank believes one reason for that could be the wealth being created in China, Russia and Brazil.

“I was talking to a wealth manager that went to the home of a billionaire oligarch who had all of these Picassos: beautiful, classic pieces of art. He said, ‘Where did you get them?’ and the Russian said, ‘I’d rather not say,’” Frank recalled.

Wittman said some art heists are well thought-out plans reminiscent of the "Thomas Crown Affair", while others are crimes of opportunity, carried out by an insider with access to the collection.

Richard Weisman has one of the most respected pop art collections in the country. In September 2009, while he was at his home in Seattle, Weisman said, a thief broke into his Los Angeles home and walked out with a set of Andy Warhol paintings insured for $25 million.

Roxane West inherited hundreds of paintings and thousands of drawings created by her aunt, abstract expressionist painter Shirley Alameda West. Roxane West never expected that the building super, whom she trusted and treated like family, would steal her aunt’s entire collection.

According to the FBI, the losses from elaborate cons and brazen thefts number in the billions every year. That, however, does not seem to be slowing down investors.

“There are now 11 million millionaires in the world and growing, but there are only so many bottles of 1945 Mouton Rothschild that they’ve made,” said Frank. “So you have a growing number of buyers, a shrinking number of collectibles, prices are going to keep going up.”