Minhang district police busted a criminal ring for producing and selling counterfeit Cartier and Bvlgari jewelry, seizing 5 million yuan ($814,500) worth of phony products, local media reported Monday.

On July 8, police arrested two brothers and a third man who ran the workshop where the products were produced, according to a report in the Shanghai Morning Post. They were all charged with counterfeiting registered trademarks.

Police confiscated 320 pieces of jewelry from the workshop, including counterfeits of Cartier diamond rings, Bvlgari rings, and Hermes belt buckles. They also found 110,000 yuan in cash.

For fakes, the jewelry was of high quality. An expert from a legitimate jewelry producer said it was difficult to tell the counterfeits from the real products, according to the report.

"The group sold the counterfeit jewelry for half of its retail price. They did not sell to individual customers, but to businessmen who then resold the products," said Hou Jianhua, a press officer with the Minhang District Public Security Bureau.

The unidentified brothers owned a jewelry store at City God Temple in Huangpu district, where they sold jewelry under their own brand. Minhang district police started looking into the store in April after police learned that the store was secretly selling jewelry under the Cartier and Bvlgari brands, the report said.

Police discovered that the brothers sourced their jewelry from a Guangdong Province man, whom they called Ah Liang.

Ah Liang ran an underground jewelry workshop out of a villa on Shangbo Road in Pudong New Area. Police found serious measures had been taken to secure the villa. Workers were only allowed to enter and leave from a door in the garage. There were surveillance cameras installed at the front door and the garage entrance, as well as above each seat in the workshop to prevent theft.

The group had hired 10 workers, all of whom lived in the villa.

Police said Ah Liang used to work for the brothers at their store, but they later put him in charge of the workshop, which was built in the villa's 10-square-meter basement.

The brothers were in charge of obtaining the raw materials for the jewelry, such as the gold and diamonds. They also handled the sales end of the operation.

The case was still under investigation Monday.