China halted leveraged trading at three leading bitcoin exchanges after the central bank launched spot checks on the platforms for possible violations, the South China Morning Post reported Jan. 19.

The People's Bank of China sent inspection teams to BTCC, OKCoin and Huobi on Jan. 11 to look into possible rule violations, such as money laundering, manipulation and unauthorized financing. The move marks the regulator's first formal probe into the market.

Staff with OKCoin and Huobi confirmed that leveraged trading had been halted, but denied media reports that said the companies provided illegal margin financing to investors and did not set up anti-money laundering systems. The staff added that the investigation is still ongoing and that final results are still pending.

Meanwhile, BTCC CEO Bobby Lee said they stopped offering margin loans in the week of Jan. 9, as did other competitors, following discussions with the central bank, Reuters reported Jan. 19. Lee did not provide further details.

Lee, however, noted that reports regarding BTCC being penalized for offering margin loans illegally were unfounded. Lee said the company has not received any verbal or written feedback from the central bank regarding the probe.

Chinese media reported earlier that the three platforms engaged in illegal margin trading and that the central bank found hidden risks in BTCC.

The central bank declined to comment on the matter, Reuters said.