Police in Central China's Henan province rounded up 33 people suspected of illegal gold-futures trading in a case involving more than 5,000 investors and at least 380 billion yuan ($59.62 billion).

The suspects, who had been trading since October 2008, had never registered with industrial and commercial authorities, as required by the law, said Guo Congbin, director of Luoyang public security bureau, on Tuesday.

They promoted investments in Loco London gold, the London gold market in Hong Kong, Guo said, which is illegal on the mainland.

According to Guo, the suspects claimed to be agents of overseas companies dealing in London gold and, with promises of huge returns, persuaded investors to establish accounts on the Internet for trading Loco London gold.

They did not inform investors of the risks of transactions or sign detailed contracts with them, and they charged exorbitant consulting fees for the deals, he said.

An investor named Ye told police that he lost 2.8 million yuan shortly after becoming involved in the trading in April 2010 under the guidance of a suspect named Wang, the Luoyang public security bureau said in a statement on its micro blog on Tuesday.

Ye deposited money into several of the suspects' private bank accounts, as instructed by Wang, the statement said.

The police found large amounts of money from the trading in bank accounts the suspects opened in Shanghai's Pudong New Area, the statement said.

Although the suspects tried to escape detection, the statement said, using mobile phone numbers registered in Shenzhen, Guangdong province, and communicating with their agents through online messaging services registered in Hong Kong, police learned they were staying in an apartment in Pudong.

Several of the suspects were caught on March 2, when police raided the apartment, the statement said, and some others were later detained in Luoyang and Shanghai.

Zhang Hui, head of the Luoyang public security bureau's economic investigation team handling the case, said that the investigation continues and more arrests will be made across China.

anbaijie@chinadaily.com.cn