More than 1,100 cultural artifacts recovered after a robbery are displayed in Xi'an. [Chen Liukun and Liang Aiping/Xinhua]

Fifty-six of the suspects were arrested and 35 are still under investigation. Five of the suspects were listed as Class A fugitives by the Ministry of Public Security.

One, a 64-year old man surnamed Meng, was regarded as the most prolific tomb raider in Shaanxi.

He was known to have funded criminal gangs and employed technical personnel to gain access to tombs.

Having spent 40 years organizing raids and dealing in stolen artifacts, Meng had established relationships with many traffickers and private collectors, who paid high prices for the stolen artifacts.

He and his associates used instant-messaging platforms and email to post photos, identify items and settle prices, according to Wang Zi, an officer with the public security department of Chunhua county in Shaanxi.

"The assessments, sample ordering and discussions about prices and payment were all carried out online," he said, adding that some of Meng's customers were senior officials, including Zhang Moping, a former political adviser in Gansu province and Zhang Xuepu, a former political adviser from Henan province.

In April, Meng was apprehended by police outside his home in Xianyang city, Shaanxi. Officers confiscated more than 70 cultural relics Meng kept in his house, including the Jade Dragon, a national-level cultural relic, and a glazed hairpin, identified as a tribute to the Western Regions during the Western Han Dynasty (206 BC-24 AD).

According to Liu Lei, Wang's colleague in the Chunhua public security department, in the past 10 years, Zhang Moping had bought 100 items from Meng.

When Zhang Moping was arrested on suspicion of purchasing stolen relics, police confiscated more than 200 items discovered at his house. He is in criminal detention.

Zhang Xuepu fled to Canada when his crimes were uncovered, and police are working closely with their counterparts in the country to repatriate him.