China, under President Xi Jinping, has shown a growing desire to embrace traditional culture. The government — which asserts ownership over all ancient tombs and underground cultural relics — has sought to combat the tomb-robbing problem through lawmaking, increased surveillance and monetary rewards for people who turn in relics.

But officials say the problem is so pervasive that it has become nearly impossible to eliminate.

“It’s just like drugs in the United States,” said Zhou Kuiying, deputy director of the Shaanxi provincial bureau of cultural heritage. “Even though the government bans tomb robbing, there are still many people who do it.”

For more than 3,000 years, Chinese rulers and aristocrats adhered to elaborate funerary rituals, including the practice of burying the dead with objects to use in the afterlife. Depending on the era and the rank and wealth of the deceased, the burial goods could include everything from jade discs and bronze vessels to lacquer boxes and glazed pottery figurines.

Grave robbing in China has a history that is perhaps as long. In the second century B.C., tomb robbing was so widespread that the Lüshi Chunqiu, a classic Chinese text compiled around 239 B.C., advocated frugal burials to deter looters. Even the mausoleum of China’s first emperor, Qin Shihuangdi, which is guarded by his famous Terracotta Army, is rumored to contain a series of booby traps intended to ward off potential robbers.

It wasn’t until centuries later, during the post-Mao opening of China in the 1980s, that this practice became an epidemic. Farmers, whose families had for generations been charged with safeguarding local tombs, began moving off the land and into cities. Vast areas were turned over to make way for subway tunnels, apartment buildings and highway networks. Construction sites doubled as archaeological pits, and countless tombs and historical relics were unearthed in the process.

Along the way, many Chinese, buoyed by rising incomes, developed a new appreciation for relics, giving rise to a new class of Chinese collectors who rival even longtime Western collectors of Chinese antiquities in their knowledge, enthusiasm and purchasing power.