The European Union Agency for Law Enforcement Cooperation, or Europol, has reported authorities took control of crypto wallets containing more than $19 million in cryptocurrency as part of enforcement actions against crypto firm Bitzlato.

In a Jan. 23 announcement, Europol reported that roughly 46% of assets — 1 billion euro, or $1.09 billion at the time of publication — moved through Bitzlato were linked to illicit activities. The government agency’s analysis suggested that Bitzlato received more than 2.1 billion euro in cryptocurrencies including Bitcoin (BTC), Dash (DASH), and Dogecoin (DOGE), much of which was converted into Russian rubles.

“While the conversions of crypto-assets into fiat currencies is not illegal, investigations into the cybercriminal operators indicated that large volumes of criminal assets were going through the platform,” said Europol. “The majority of suspicious transactions are linked to entities sanctioned by the Office of Foreign Assets Control (OFAC), with others linked to cyber scams, money laundering, ransomware and child abuse material.”

As part of actions by a cryptocurrency-focused enforcement team, U.S. authorities announced on Jan. 18 they had arrested Bitzlato founder Anatoly Legkodymov in Florida. Europol added that the operation, which involved support from agencies in Belgium, Cyprus, Portugal, Spain and the Netherlands, resulted in the arrest of 4 other individuals linked to the crypto exchange — 1 in Cyprus and 3 in Spain.

Related: Bitzlato kept a low profile, but did not go entirely unnoticed before DOJ action

In addition to the arrests, Europol reported authorities had seized wallets worth roughly 18 million euro, or $19.5 million, and frozen more than 100 accounts at other crypto exchanges which controlled 50 million euro. U.S. authorities were also involved in efforts to seize Bitzlato’s servers for allegedly being a “primary money laundering concern” connected to Russian illicit finance.

Legkodymov was reportedly arraigned in U.S. District Court for the Southern District of Florida on Jan. 18 following his arrest. It’s unclear what charges, if any, his associates at Bitzlato may face in Europe.