Chinese authorities have arrested 175 people in the country’s biggest ever operation to recover stolen artifacts.

China’s Ministry of Public Security said 1,168 cultural relics worth more than 500 million yuan ($80 million) had been found.

The artifacts are thought to be illegally excavated in Niuheliang, a Neolithic archaeological site in north-eastern Liaoning province.

The Ministry of Public Security said the activities of the looters had severely damaged the site.

Among the artifacts was a coiled jade dragon, one of the earliest known depictions of the mythological creature, authorities said.

The Niuheliang archaeological site, which dates back 5,500-5,000 years, was a burial and sacrificial centre in the late Hongshan period, according to UNESCO.

Chinese state media described the recovery as the biggest operation of its kind since the founding of modern China in 1949.

The date of the recovery operation was not provided, but the ministry said in a statement that 1,000 police officer were involved.

The looters were said to be split into 10 gangs that were responsible for everything from the excavation to the selling of the relics, China Daily reports.

Four archaeologists are also thought to be involved, the newspaper said.