U.S. claims $400 million from Helix, a notorious bitcoin mixer used on the darknet

The U.S. government now has the legal title to more than $400 million worth of seized cryptocurrency, real estate and cash linked to the once-popular darknet bitcoin mixing service Helix, the Department of Justice (DOJ) announced on Thursday. Mixing services like Helix are designed to obscure the origin and destination of crypto transactions by pooling and redistributing funds, a practice long scrutinized by law enforcement and regulators. The DOJ alleged that Helix in particular was used by drug traffickers and other criminals to launder money.

According to court documents, Helix was among the most widely used mixing services on the darknet, particularly by online drug dealers seeking to launder illicit profits. Investigators said Helix processed at least 354,468 bitcoin, valued at roughly $300 million at the time, much of it tied to darknet drug markets. Helix’s operator, Larry Dean Harmon collected commissions and fees on these transactions.

Harmon pleaded guilty in August 2021 to conspiracy to commit money laundering and was sentenced in November 2024 to 36 months in prison, followed by three years of supervised release, along with a forfeiture money judgment and the forfeiture of seized property.

Harmon also operated Grams, a darknet search engine designed to connect users to major darknet markets. Helix’s application programming interface (API) allowed darknet marketplaces to integrate the mixer directly into their bitcoin withdrawal systems, enabling seamless

Since 2020, the DOJ Criminal Division’s Computer Crime and Intellectual Property Section (CCIPS) has secured more than 180 cybercrime convictions and court orders for the return of over $350 million in victim funds, according to the Justice Department.