In his latest letter to the U.S. Justice Department and Treasury on Friday, Sen. Richard Blumenthal is digging into Binance's anti-money laundering compliance, following reports that the crypto exchange enabled billions in sanctions evasion by Iranian entities.

In the letter sent Friday, Sen. Blumenthal, D-Conn., specifically honed in on monitors that Binance had to put in place after the exchange pleaded guilty in November 2023 to failing to register as a money transmitting business and breaching sanctions. The exchange agreed to pay over $4 billion in penalties and also agreed to retain an "independent compliance monitor" for three years.

Binance's former CEO Changpeng Zhao was also charged and served four months in prison. In October, President Donald Trump pardoned Zhao.

Binance has come back into the spotlight recently after reports from The New York Times, Fortune, and The Wall Street Journal found that Binance compliance staff found that two Binance partners, Hexa Whale and Blessed Trust, acted as middlemen for money laundering and allowed trade with Iranian government entities. According to the reports, people involved in the investigation of the Iranian transactions were disciplined or dismissed, although Binance has disputed this.

Blumenthal previously sent a letter to Binance CEO Richard Teng about reporting on potential sanctions violations. The lawmaker is also the top Democrat of the U.S. Senate Permanent Subcommittee on Investigations, which is tasked with analyzing compliance with laws and crime.

"In early 2026, reporting stated that Binance had facilitated billions of dollars of sanctions evasion for Iran-linked entities," Blumenthal said in his letter. "These reports raise questions regarding the extent to which the company has adhered to its 2023 settlements."

In 2025, Bloomberg reported that Binance was close to coming to a deal with the DOJ to drop its compliance officer ahead of schedule. In his letters on Friday, Blumenthal asked about the status of that monitor and if that person had filed any misconduct reports, among other documents. He asked for a response from the exchange by April 24.

The letter was sent to the Treasury's Financial Crimes Enforcement Network Director Andrea Gacki and DOJ Acting Attorney General Todd Blanche. The DOJ and FinCEN did not immediately respond to a request for comment. Binance declined to comment.