German authorities have shut down the world’s largest illegal marketplace operating on the darknet, with assistance from U.S. law enforcement agencies.

The platform, known as Hydra Market, was a Russian-language marketplace that had operated on the Tor network since at least 2015. According to German officials, Hydra was a major hub for drug trafficking and had approximately 17 million registered users. Customers also traded forged documents and stolen credit card data through the platform.

In 2020 alone, Hydra recorded sales of more than €1.23 billion, making it the highest-grossing illegal marketplace worldwide.

German federal police said they seized Hydra’s server infrastructure and approximately $25 million worth of bitcoin during coordinated raids on Tuesday.

“The seizures carried out today were preceded by extensive investigations conducted since August 2021, involving several U.S. authorities,” German federal police said in a statement.

U.S. agencies involved in the operation included the Drug Enforcement Administration (DEA), IRS Criminal Investigation, and other federal law enforcement bodies. The investigation focused on identifying and dismantling Hydra’s operators and administrators, authorities said.

In addition to facilitating criminal transactions, Hydra was allegedly used for money laundering and offered services designed to obfuscate cryptocurrency transactions, making them harder for law enforcement to trace.

Alongside the takedown, the U.S. Treasury Department announced sanctions against Hydra and Garantex, a virtual currency exchange based in Estonia. Treasury officials said Garantex had processed more than $100 million in cryptocurrency transactions linked to illicit actors.

“The global threat of cybercrime and ransomware originating in Russia, and the ability of criminal leaders to operate there with impunity, is deeply concerning to the United States,” Treasury Secretary Janet Yellen said. “Our actions send a message that criminals cannot hide on the darknet or anywhere else in the world.”

According to the Treasury Department, Hydra accounted for approximately 86% of illicit Bitcoin transactions in Russia in 2019. Although Estonian authorities revoked Garantex’s operating license in February, the exchange continued operating through what officials described as “unscrupulous means.”

The sanctions form part of a broader effort by the Biden administration to demonstrate that virtual currencies cannot be used to evade U.S. or international sanctions, particularly those targeting Russia and global criminal networks.

The Treasury Department’s Office of Foreign Assets Control said it will continue monitoring attempts to bypass sanctions using digital assets and will take enforcement action where violations occur.