Of course, many art works never come up for auction. Perhaps the greatest enigma in Chinese art today is a little-reported crime wave in Europe that, since 2010, has targeted antiquities that were looted from the Old Summer Palace or from Beijing’s Forbidden City in the early 20th century.

The string of thefts is believed to have started in August 2010 with a break-in at the Chinese Pavilion on the grounds of Drottningholm Palace, the royal residence near Stockholm. Five months later, burglars in Bergen, Norway, made off with 56 items from the China Collection of the KODE Art Museums, mostly antiquities gathered by Johan Wilhelm Normann Munthe, a military adventurer who served in the Boxer Rebellion.

In April 2012, intruders broke into the Malcolm MacDonald Gallery at the Oriental Museum at Durham University in England, filching a porcelain sculpture and jade bowl together valued at about $3 million. That same month, thieves made their way into the Fitzwilliam Museum at Cambridge University, making off with 18 “culturally significant” objects, notably Chinese jades.

In January 2013, some 25 Chinese artworks were stolen in a second theft at the museum in Norway. The museum closed its China Collection to visitors and, in an arrangement brokered by a Chinese entrepreneur, seven of 21 marble plinths taken from the Old Summer Palace were promised to Peking University.

Finally, only three months ago, burglars pilfered 15 gold, bronze and porcelain masterworks in the Château de Fontainebleau, the former royal retreat south of Paris. In a seven-minute sweep, they outwitted alarms and cameras as they smashed display cases within the palace’s Chinese Museum, founded in 1863 by Empress Eugénie, wife of Napoleon III. “They knew very well what they were after,” said the chateau’s president, Jean-François Hebert.

Why steal documented works that can neither be legally sold nor openly exhibited? “Chinese laws, on everything from theft to intellectual property, are very different from those in the West, and therefore stolen or forged artworks find a market far more easily there than abroad,” Noah Charney, an art crime expert, said after the Norway thefts. “A certain type of Chinese collector would be far less shy about purchasing a knowingly stolen artwork than a Western collector would. Chinese collectors could purchase stolen Chinese art and still have the pride of display, perhaps with the rationale that, whether or not the object was stolen, it should be in China, and therefore the collector was somehow aiding its liberation.”

As Paul Harris, a leading British dealer of Chinese art, wrote in a blog post in March: “The general feeling in intelligence circles is that this was ‘an ordered job’ carried out by local French professional criminals acting as agents for a third party. That third party is almost certainly abroad, well away from French jurisdiction and, according to one intelligence expert, ‘The smart money is on the artifacts being on the way to the People’s Republic of China.’ ”