China National Radio (CNR), a high-level government mouthpiece, has aired doubts about the legality of services offered by OKEx, the Hong Kong-based cryptocurrency exchange launched by OKCoin, previously one of the "Big Three" trading platforms in China.

Through its podcast channel "Voice of China" on Thursday and later an article titled "Exchanges that still prevail after the ban," CNR alleged that OKEx violated rules by offering bitcoin contracts to mainland Chinese investors after it claimed to have moved its business overseas.

The broadcaster cited two sources with the surnames Yang and Zhang, allegedly investors who had used OKex's services, claiming that the firm's bitcoin contracts trading is essentially betting on unregulated bitcoin futures with the option to add leverage to increase returns, and risk.

The article went on to blast OKEx for apparently dodging regulations by registering itself in Belize, while having its headquarters based in Hong Kong, a special administrative region outside of mainland China's jurisdiction.

Furthermore, citing its own investigations, the station alleged that OKEx's technological development is still managed by the OKCoin team based in Beijing. In the meantime, CNR said the exchange has continued to offer over-the-counter (OTC) trading that makes cryptocurrency buying and selling available for investors from mainland China.

Notably, today's article forms part of a cryptocurrency investigation series currently being broadcast by the state media outlet.

On Wednesday, CNR aired and published an article written by the same team, taking aim at ICOs that are still offering tokens to Chinese investors even after the notable ban on fund-raising token sales by the People's Bank of China last year.

Citing a former employee of a cryptocurrency project named PROChain, the station specifically alleged the firm, the team of which is mostly China-based, violated regulations by selling tokens to domestic investors without providing substantial technological blockchain development.

Neither PROChain nor OKex have yet responded to CoinDesk's requests for comment.

CNR image via Shutterstock