In early December 2025, European law enforcement agencies seized Cryptomixer.io, a well-known crypto tumbler.
Since 2016, Cryptomixer.io served the clearnet, also know as the surface web, and the dark web. As a tumbler, the platform processed large amounts of cryptocurrency over extended periods to block and erase traces of illegal origins. This involved repeated, random distribution of cryptocurrency across multiple platforms for varying periods of time to prevent tracing through the blockchain. According to Europol, the site laundered cryptocurrency for a variety of bad actors, including groups and individuals involved in:
- Weapons and drug trafficking
- Ransomware and credit card fraud
- Nation-state hacking
- Crypto crime, tax evasion and tax fraud
Just as laundering money as cash eventually obscures or “cleans” the money, bitcoin processed through a tumbler is difficult to trace. The value of the cryptocurrency is eventually returned to the owner.
Operation “Olympia”
In early December 2025, Swiss and German law enforcement reported they had acted against Cryptomixer.io, seizing and shutting down the platform during Operation Olympia. During the raid, agents seized three servers in Switzerland containing more than 12 terabytes of information. In addition, more than 12 million euros in Bitcoin were confiscated. Officials posted a banner on the website noting that it had been seized as part of Operation Olympia.
Since its launch, Cryptomixer.io is believed to have mixed more than 1.3 billion euros in Bitcoin. A graphic novel-style video published by Europol outlines how cryptocurrency laundering is used to erase traces of criminal activity.
Not all crypto tumblers are engaged in illegal activity, as some users seek privacy without having criminal intent. In the case of Crytptomixer.io, however, the platform was widely regarded as a money-laundering operation.
Operation Olympia was conducted by the Joint Cybercrime Action Taskforce (J-CAT), an international law enforcement group located in The Hague. While the U.S. Federal Bureau of Investigation (FBI) and the U.S. Secret Service are non-European members of J-CAT, it remains unclear what role the United States will play in future enforcement efforts, particularly amid evolving approaches to cryptocurrency regulations and enforcement.
Cryptocurrency values remain volatile around the world, yet crypto continues to attract interest. For those that can afford to lose what they invest, crypto remains a high stakes game of win or lose. For Cryptomixer.io in late November 2025, it was a loss.
Strategic Guidance for Tax Fraud and Crypto-Related Investigations
If you are facing allegations involving crypto transactions, money laundering or tax fraud, early legal guidance matters. Enforcement actions like Operation Olympia demonstrate how quickly digital assets can become the focus of international investigations—and how financial activity once thought to be private can surface in enforcement actions.
Our legal team provides strategic counsel for individuals and businesses navigating IRS investigations, tax controversies and potential criminal exposure. To better understand how tax fraud investigations unfold—and what steps to take if you are at risk—download our comprehensive "Understanding Tax Fraud" ebook. It outlines common enforcement triggers, investigative tactics, and key considerations for protecting your rights.
To discuss your specific situation, schedule a confidential consultation or call 440-250-9709. We represent clients nationwide and internationally from our offices in Cleveland and Chicago.
