This statistic should make art enthusiasts think twice before spending big bucks on the next item for their collection.
"About 40 percent of everything in the art market is fake," says Curtis Dowling, a leading forgeries expert. "Thomas Hoving, who was the director of the Metropolitan Museum of Art in New York, once said that 40 percent of all his collection was fake. He just wished he knew which 40 percent it was."
If the experts have a hard time separating the masterpieces from the frauds, what chance do the rest of us have?
Dowling will show TV viewers what it takes to spot a forgery in Treasure Detectives, CNBC's first reality series, which premieres at 8 p.m. Tuesday.
Not that most of us are spending tens of thousands of dollars to acquire Roy Lichtenstein prints, Lalique glass automobile hood ornaments and Honus Wagner baseball cards.
Museums, auction houses and millionaire collectors are the ones being duped on that grand scale.
Still, the lessons taught on Treasure Detectives can benefit one and all.
No matter how big or small your collecting budget is, Dowling stresses that the phrase "caveat emptor" (or "buyer beware") should always be in the back of your mind.
"There are 1,500 Beatles signatures sold every month on the Internet, and only 6 percent of them are real," he says. "That's a bad batting average, yet these things are still selling because people are too willing to believe they're getting the genuine article."
All this kind of crime takes is some unscrupulous person buying a $10 baseball, faking a famous ballplayer's signature on it and selling his handiwork online for $70 or $80 to a motivated buyer.
Dowling calls that "fast food forgery."
Treasure Detectives focuses on higher-stakes fakes, but the principle is the same: Buyer beware.
"Amazingly, there isn't a program on television that does this," Dowling says. "There are many shows that put art and antiques on the television, like Antiques Roadshow, and the conversation is about the value of these items. But what if the artwork or the antique is a fake? Ours is the first show that does this."
Treasure Detectives features Dowling and a team of experts combining old-fashioned common sense, a lifetime of acquired knowledge and some high-tech science to separate the gems from the forgeries.
Some fakes are so brilliantly executed, in fact, that Dowling has a begrudging admiration for them.
"Forgery is no less a skill than anything else," he says. "And some of the forgeries I've had the experience of investigating are astounding. The skill of the maker, someone who devotes three years of his life to re-create a da Vinci, for example, he's a master in his own right and it can take your breath away."
There also are times when Dowling can't come to a conclusive ruling on a piece.
"I had an item last year," he says. "I worked on it for seven months, and we just couldn't be sure whether it was real or fake. It's frustrating and luckily this doesn't happen very often. But sometimes there are going to be items you can never be sure about. Sometimes you just have to walk away from that item."
Sound words of advice, whether your budget is $50 or $50,000: Just walk away.