Stablecoin issuer Tether said it has frozen about $4.2 billion of its USDT tokens over links to “illicit activity,” with most of the freezes occurring in the past three years, as authorities worldwide intensify efforts to curb crypto-related crime, Reuters reported.

Tether, the world’s largest stablecoin company, has more than $180 billion of its dollar-pegged token in circulation, up from around $70 billion three years ago, according to the report. The company can remotely freeze tokens held in users’ crypto wallets when asked by law enforcement.

This week, Tether said it helped the U.S. Justice Department freeze nearly $61 million in USDT tied to “pig-butchering,” a fraud in which scammers build personal relationships with victims, Reuters reported. A Tether spokesperson told the news outlet in emailed comments that the action brought total frozen assets linked to illicit activity to $4.2 billion, including $3.5 billion frozen since 2023.

Tether has previously said it blocked wallets linked to human trafficking and to “terrorism and warfare” in Israel and Ukraine, Reuters said. The sanctioned Russian crypto exchange Garantex said last year that Tether had blocked funds on its platform.

Authorities have long raised concerns about the role of crypto in illicit finance, Reuters noted, citing the Financial Action Task Force’s call last year for countries to take stronger action against illicit finance in crypto markets, which are generally less regulated than mainstream financial markets.

In January, blockchain analytics firm Chainalysis said that the illicit on-chain money laundering ecosystem expanded from about $10 billion in 2020 to more than $82 billion in 2025, a jump it attributes to the growing liquidity and accessibility of crypto as well as a structural shift in who provides laundering services and how those services operate. 

That surge has been driven in part by Chinese-language money-laundering networks have become a central conduit for the criminal exploitation of crypto-assets, the company said. Such networks account for 20 percent of known on-chain laundering over the last five years, and accounted for $16.1 billion in illicit crypto payments last year, or roughly $44 million per day. 

Read more at Reuters