Cryptocurrency platform JPEX shut down some trading during an ongoing investigation by the Hong Kong police.

Users won’t be able to place new orders on its Earn Trading interface from Monday, according to a statement Sunday, referring to some wealth management products. JPEX is negotiating with third-party market makers to resolve a liquidity shortage, the statement said.

Hong Kong police are investigating JPEX after a referral from the Securities and Futures Commission, the markets regulator. The SFC has said the firm was operating in the city as an unlicensed entity, the first such warning by the watchdog since the country boosted efforts to grow Hong Kong’s presence as a crypto hub by luring more individual investors.

JPEX said market makers had frozen funds following probes by Hong Kong authorities. Existing orders on Earn Trading will continue until the product’s maturity, it said. JPEX didn’t respond to a request for comment.

Hong Kong police has received 83 complaints on JPEX involving HK$34 million ($4.3 million), according to a media report, citing Police Commissioner Raymond Siu on Saturday.

JPEX is headquartered in Dubai, according to its website.