The US Department of Justice announced a “major international cryptocurrency enforcement action” against crypto company Bitzlato and the arrest of its founder Anatoly Legkodymov.

In a Jan. 18 announcement, U.S. Deputy Attorney General Lisa Monaco said authorities had taken enforcement action against Bizlato in coordination with France, seizing Bitzlato’s website and labeling the company as a “primary money laundering concern”. which is related to Russian illegal financing. According to Monaco, the Justice Department worked with the Treasury Department and French law enforcement to take action against Bitzlato for allegedly “operating a money transfer business that transported and transferred illegal funds and failed to comply with U.S. legal safeguards.”

As part of the case against Bitzlato, FBI officials arrested Legkodymov, a Russian who lives in China, in Miami on January 17. He is about to be arraigned in the United States District Court for the Southern District of Florida.

US authorities said the criminal charges against Bitzlato were based on the company being a “critical financial resource” for the Hydra darknet marketplace, allowing users to launder money, including those from ransomware attacks:

“Users of Hydra Market exchanged more than $700 million in cryptocurrency with Bitzlato, either directly or through brokers, until Hydra Market was shut down by US and German law enforcement in April 2022. Bitzlato also received more than $15 million in ransomware proceeds.”

The enforcement action was a coordinated effort across Europe and the US to seize many of Bitzlato’s assets – including the company’s servers – and to take the founder into custody. Monaco called the case the “most important enforcement effort” against an exchange since the launch of the National Cryptocurrency Enforcement Team in October 2021.

Related: Crypto Cleaning Up: How Much Enforcement Is Too Much?

Assistant Attorney General Kenneth Polite of the Justice Department’s criminal division suggested that US authorities had “just begun” a crackdown on similar companies involved in facilitating money laundering. While no official directly commented on the ongoing case against crypto exchange FTX and its former CEO Sam Bankman-Fried, Monaco referred to crimes against the US financial system “from a tropical island”.

This story is in development and will be updated.