Chinese police identified what they called an "underground bank" providing illegal currency conversion services.
The operators exploited crypto's anonymity and ease of cross-border transfers to provide the service, China News Service reported.
Chinese police arrested six people involved in using cryptocurrency to provide an illegal currency conversion operation that handled some 2.14 billion yuan ($296 million), according to a China News Service report published on Weixin.
The "underground bank" was uncovered by the Public Security Bureau of Panshi City, Jilin, the state-owned news service said.
The operation used domestic accounts to receive and transfer funds while exploiting the anonymous, borderless characteristics of over-the-counter virtual currency trading to exchange between the yuan and South Korean won. Users included Korean purchasing agents, e-commerce firms and import/export companies, among others, according to the report.