By Laura Murphy, fine art specialist, Chubb PersonalInsurance

Every year, more than $6 billion in art is stolen worldwide.Major works of art are being carried out of museums and beingpilfered during times of political upheaval. In addition, forgeriesare being passed off as original artworks by well-knownartists.

With so many works of art being looted, it can be difficult toknow if the piece your client is insuring has a checkered past.That's because the art black market, according to Interpol, is thefourth largest criminal network in the world. Within such athriving, intricate web of crime, art can disappear quickly. Onceunderground, a piece can be sold and resold, often for decades,without detection. Once a piece changes hands a few times, itsorigins are lost, making it easy to purchase a stolen work of artwithout knowing.

Even museums have a difficult time knowing the history, orprovenance, of a piece. Since 2006, American museums have returnedmore than 100 statues, bronzes, vases, mosaics and other works ofart to foreign countries. While they were under no legal obligationto do so in many cases, the museums chose to return the pieces onceprovenance was determined.

Collectors buying through dealers assume the piece islegitimate, and most of the time, that's true. Still, buyers shouldconduct their own due diligence to ensure they're not purchasingsomething questionable.

Here are some things buyers can do at the point of sale:

• Obtain a certificate of authenticity: Ifthe piece is by an artist who is still alive, obtain acertificate of authenticity from thatartist.
• Check the Art Loss Register: Collectorscan check their potential purchase against the registry, which is an international database of lost andstolen artwork. Most legitimate dealers and auction houseswill cross-reference any purchases with the Register. Theregistry typically houses an image of the piece along with afull description and, potentially, which collection it wasin.
• Work backward: Collectors can track thepiece's history, including the last owners and where it wasshown or has appeared. That makes it easier to see howthe organization acquired the piece.
• Evaluate auction records to determine priorownership and dates of sale: Collectors shouldrequest auction records and sale records, making note of datesand locations. Once objects are stolen, they'll be sold viathe black market, or they'll exchange hands several timesuntil some unknowing buyer purchases it.
• Search the artist's foundation: Collectorscan locate information on art by deceased artists throughvarious foundations dedicated to that particular artist'swork. Foundations can also connect collectors to renownedexperts in that artist's work, who can then authenticate thepiece.
• Be aware of dates: Look for possiblered-flag dates, including those around periods of war orpolitical upheaval. For example, art sales during 1935 to 1945could in fact be looted pieces obtained during World War IIand may have forged documentation. In cases where the originalowners were Holocaust victims, the pieces may never have beenreported missing.
• Pay attention to the country of origin: If acountry has gone through a civil war, military action orpolitical strife, there is a greater possibility that lootingof artwork has occurred during these times of limitedgovernment oversight of their cultural heritage sites. Forexample, Middle Eastern or Southeast Asian countriesunderwent upheaval, and many of their art treasures werelooted. Looters were known to break statues into smallerpieces and sell them off separately.
• Look for cultural patrimony laws: Manycountries will have cultural patrimony laws, which meansobjects of historical significance are not allowed to leavethe country. For instance, the Metropolitan Museum of Artrecently discovered and returned to the Cambodian governmentsome sculptures that were found to have been illegally removedfrom the country.
• Employ experts: Even with due diligenceon the buyer's part, there is a chance that older piecescannot be verified with 100-percent accuracy. Withnewer pieces, it's easier to confirm authenticity, but olderpieces require the assistance of experts. When in doubt, hirean expert whose specialty is that of the artist who createdthe work. Experts can quickly determine the authenticity of apiece, and may be aware of any history of stolen pieces fromthat artist's collection.

Nowadays there are scientific methods to verify the authenticityof an item. Tests on pigments and fibers can determine the era inwhich a piece was created.

Recently, forensic testing has also helped collectors withauthentication. For example, the estate of artist Ruth Kligman hasbeen trying for years to authenticate a work purportedly by JacksonPollack. A forensic investigation revealed a hair on the canvasthat matched a polar bear rug that was known to be in Pollack'sliving room. Still, even with forensic testing, occasionally therewill be disputes between the forensics team and the experts on thatparticular artist. That can create a gray area.

Instead, collectors should create their own paper trail. Weencourage clients to keep a detailed record of their items,including the artist, title, medium, dimensions and any identifyingmarks or sale stickers on the back of the canvas, etc. If a work isstolen, having a detailed description of the item will helpfacilitate its recovery.

Even so, sometimes strong provenance does exist but it is deniedby the artist. There was a case in the 1990s in which Balthus, aPolish-born painter who worked in France, disavowed a painting soldby a former wife. The case ended in court, where it was revealedthe artist was lying out of retribution. The work was confirmed asauthentic.