Beijing police officers exam stolen relics in December 2013. Photo: CFP

Yao doesn't look like one expects a career criminal to look. He doesn't wear gold chains and his arms are free of tattoos. But the 53-year-old's over 30 years of experience in illegally excavating tombs and his expertise in using feng shui to locate loot has made him the central figure in China's largest-ever seizure of tomb raiders, the Beijing Times reported on Wednesday.

Chinese police recently announced that they had arrested 175 people from ten gangs in connection with a large-scale crackdown on tomb raiders in the city of Lingyuan, Liaoning Province. Police recovered 1,168 cultural relics worth more than 500 million yuan($80 million).

Criminal techniques

In what is described as the biggest bust of its kind since the People's Republic of China was founded in 1949, the nine-month long operation involved more than 1,000 police officers and cross-regional cooperation by the authorities in Liaoning, Heilongjiang, and Henan provinces and the Inner Mongolia Autonomous Region.

The tomb raiders are suspected of conducting illegal excavations in Niuheliang, a Neolithic site in Chaoyang, Liaoning.

The area is known for the Hongshan Cultural Relics Site, in which the earliest known signs of Chinese civilization, dating back more than 5,000 years, have been found.

Many of the artifacts retrieved are unique, and according to government officials the bust has filled in the blanks regarding China's archeological development.

The recovered artifacts include jade items, porcelain dating back from 5,000 to 6,000 years ago, as well as a coiled jade dragon, one of the earliest known representations of the Chinese totem.

One of the accused, an artisan at an archaeological institute in Liaoning, allegedly stole the coiled jade dragon from a salvage excavation site in September 2010 and sold it for 3.2 million yuan in 2012.

The gangs, active in seven provinces and regions and 10 cities, have developed sophisticated techniques to locate their targets, from using traditional methods like feng shui and astrology to modern high-tech equipment, according to the Beijing Times.

Feng shui is one of the major criteria many Chinese people use when picking their burial site. Believers think a graveyard with good feng shui, such as a location that has water running in front of the grave, can protect the owner's offspring and bring them good luck and fortune. Tomb raiders simply look for locations that have good feng shui and check if there are any ancient graves nearby.

Police said that the tomb raiders also had an established network through which they could quickly move the excavated artifacts onto the black market and make huge profits.

The gangs have also improved their technology over times. Some gangs use magnetic field detectors to search for possible targets.

Four archeologists are suspected of participating in the tomb raids and helping to sell the stolen artifacts, according to crienglish.com.

Career crook

At the center of the storm is Yao, a native of Inner Mongolia, who is known for his reticence and being an expert in locating tombs with valuable artifacts.

Yao learned his tomb-raiding skills from his father, who intended to pass his "legacy" to Yao's older brother, but later taught Yao who was apparently smarter and a faster learner.

Yao was the leader of one of the ten gangs, which are intractably linked. As the "commander in chief" of his team, Yao used to explore potential sites during the day and lead his team to excavate tombs at night. The gang leader is known for his relentless persistence in excavation and will not leave a site until he finds what he is looking for.

During the process, only the most trusted members will actually be directly involved in the excavation, while the others will stand by at the site.

Despite his talent, Yao is also known for his dishonesty and often divided the gang's profits unfairly, which led to his own younger brother leaving the gang and starting his own.

"When he knew we were about to get something valuable from the site, he would always stop us and finish the work by himself. So we never know for sure how much have we got and earned," one of the gang members said.

Yao did not manage to hold on to his ill-gotten gains because of his gambling habit. One of his gang members said that Yao would gamble in Hebei and Liaoning. Several times, when Yao had let his money slip between his fingers, the tomb raider even had to use the artifacts as collateral to get away from his debt.

His gang members also revealed that Yao's son was also involved in tomb raiding.

After setting up his own gang, his brother learned from Yao's mistakes and the new gang was more organized and divided all gains equally. Making use of their established black-market network, the new gang was also able to sell their artifacts in very short period of time.

A difficult battle

"They usually excavate in deserted areas very late at night, which made their crime very difficult to detect," Wang Hongyan, a senior official of the Public Security Bureau in Chaoyang, told the Beijing Times.

But they were discovered last June when police on patrol found traces of excavation on the ground. The police then started their investigation and spent five months locating and identifying the gangs.

China's rich historical treasures are under threat from increasingly aggressive and sophisticated tomb raiders, who destroy precious archaeological assets as they swipe relics.

Stopping these criminals has posed a particular challenge to Chinese authorities, with valuable artifacts scattered over thousands of sites, many in remote locations.

Last year, in what local authorities described as the "biggest ever" find of illegally excavated relics in the city of Shaoxing's history, Zhejiang authorities detained over 120 alleged tomb raiders in a massive police operation, seizing 1,335 relics, according to news website zjnews.zjol.com.cn.