The US Justice Department announced Wednesday it has taken action against a China-based crypto exchange platform and arrested its founder.

Deputy Attorney General Lisa Monaco described the move as "a significant blow to the crypto crime ecosystem" at a news conference.

The founder of the Hong Kong-registered platform, Bitzlato, Anatoly Legkodymov, a Russian national, was arrested in Miami, Florida by FBI agents, she said.

The charges allege that he operated a high-tech financial hub catered to "known crooks," Monaco said, arguing that Bitzlato facilitated the transmission of hundreds of millions of dollars in illicit funds fueling the darknet market and laundering the proceeds of ransomware attacks.

Bitzlato was a crucial financial resource for the notorious Hydra Darknet market -- the world's longest-running and largest Darknet marketplace, responsible for 80% of the world's darknet transactions, according to the official.

Monaco said Hydra and Bitzlato formed a high-tech axis of crypto crime, which included illicit purchases of illegal drugs, stolen financial information, hacking tools from crypto accounts that amounted to more than $700 million in transfers between 2018 and 2022.

She said the recent actions "put all of those who seek to exploit the cryptocurrency ecosystem on notice," stressing that the US and its partners will use all of their tools "to attack the criminal use of the Darknet and cryptocurrencies," and Washington is taking steps to address the crisis of confidence in the crypto market.

"We will not hesitate to expose and hold accountable virtual asset service providers, darknet markets, or anyone else facilitating cyber criminals," said Deputy Treasury Secretary Wally Adeyemo.

Assistant Attorney General Kenneth A. Polite, Jr. of the Criminal Division said Bitzlato helped criminals hide transactions "behind the anonymity of the blockchain."

US Attorney Breon Peace from the Eastern District of New York said Bitzlato allowed users to open accounts with minimal identifying information, which made the platform "a safe haven for criminals," including drug dealers and ransomware groups.

He said Bitzlato's executives communicated on an encrypted chat system about the proliferation of drug dealers and the company conducted its business in a "brazenly lawless manner."

FBI Associate Deputy Director Brian Turner said more than $15 million in ransomware proceeds have been laundered through Bitzlato, making the exchange platform "a clear enabler for ransomware actors."

He stressed that the fight against cybercrime involves going after all key parts of that criminal ecosystem -- actors, finances and supporting infrastructure.