The Hong Kong Commercial Crime Bureau (CCB) is conducting a preliminary investigation into alleged unlawful activities that may have occurred at defunct bitcoin exchange MyCoin.

The CCB reports that 43 investors between the ages of 21 and 71 years old lost anywhere between HK$50,000 to HK$15m each when the exchange ceased operations. Such estimates would place the total consumer loss at HK$63m, or $8.12m at press time.

Local media reported Monday that the total losses could have been as high as $387m, however, these figures were based on the exchange's own estimates of its business volume.

Hong Kong lawmakers are now urging the government to impose a ban on bitcoin. In total, more than 25 customers in a MyCoin fraud case approached the police with their statements against the bitcoin exchange.

Former customers who spoke to the police were reportedly accompanied by lawmakers Leung Yiu-Chung and James To.

"The government should not just stand aside," Leung said. "It's simply not enough to just ask people to exercise caution when investing ... It has to ban the circulation of such virtual currency in the market."

The push for a bitcoin ban follows a Tuesday statement by the Hong Kong Monetary Authority urging consumers to “stay vigilant and guard against unscrupulous practices” in any investment activity.

CoinDesk reached out to the Hong Kong police but did not receive an immediate response.