Binance is under investigation by U.S. federal prosecutors over possible violations of sanctions against Iran.

On Sept. 22 (local time), blockchain media outlet CoinPost reported that the probe is led by the Manhattan federal prosecutor’s office in New York. The U.S. Department of Justice’s criminal division is also reviewing the matter.

The probe is focused on whether Binance ignored certain transactions even after being aware of them. Authorities are also investigating the company’s overall compliance system, CoinPost reported. That means the scope has expanded beyond checking transactions to the level of internal controls.

Binance already reached a major settlement with U.S. authorities in November 2023. At the time, the company admitted violations of anti-money laundering laws, operating an unlicensed money-transmission business and breaches of sanctions-related laws, and pleaded guilty. The penalties totaled about $4.3 billion. Co-founder Changpeng Zhao (CZ) stepped down as chief executive officer and was sentenced to four months in prison.

Since then, the Justice Department and the Treasury Department have each appointed independent monitors to oversee Binance’s implementation of compliance improvements. The latest probe again shows that Iran-related allegations have not been resolved even after that settlement.

This year, Iran-related allegations involving Binance have been raised repeatedly in the United States. In February, it was suggested that about $1.7 billion worth of funds may have flowed to Iran-related entities between March 2024 and August 2025. Reports also said an official who had led an internal investigation at the time was fired.

Political moves also continued. Senator Richard Blumenthal began a Senate inquiry on Feb. 25, and on April 17 sent a letter to the U.S. Department of Justice and the Treasury Department’s Financial Crimes Enforcement Network (FinCEN) demanding monitoring and document submissions. The deadline was set for April 24.

Binance has continued to deny the allegations. The company repeatedly said it had no accounts that traded directly with Iranian entities, and it also filed a defamation lawsuit against Dow Jones, the parent company of the Wall Street Journal. CEO Richard Teng also countered claims that transactions by Iran-sanctioned parties led to funding for Iran’s Islamic Revolutionary Guard Corps, calling them a “fundamental factual error”.

Markets are watching whether the issue will prompt renewed questions about Binance’s management of regulatory risks rather than its business continuity. Additional allegations have persisted even after it accepted a major settlement and monitoring regime. Attention is now focused on how far U.S. authorities can identify specific transaction violations and whether the existing monitoring system actually worked.