The U.S. Treasury Department has taken a strong stance against three Mexican financial firms, alleging their involvement in laundering substantial amounts of money linked to fentanyl trafficking by drug cartels. This action comes as the administration intensifies its war on illicit opioids. The firms named—Vector Casa de Bolsa, Intercam Banco, and CIBanco—are facing restrictions on certain financial transactions, a move that could aggravate relations between the United States and Mexico amid an ongoing crackdown.

The accusations raised eyebrows particularly due to Vector Casa de Bolsa, a prominent brokerage firm controlled by Alfonso Romo, a former chief of staff under ex-President Andrés Manuel López Obrador. In a statement, Vector firmly denied the allegations, asserting that it follows stringent regulatory standards and that the transactions cited by the Treasury were legitimate dealings with legally recognized companies.

Responding to the U.S. actions, Mexico’s Finance Ministry announced it has sought evidence supporting the Treasury’s claims but has so far received no proof linking the firms to any illegal activities. They also stressed that the wire transfers flagged by the U.S. were routine exchanges between Mexican and Chinese businesses, numbering in the thousands.

The growing scrutiny on these financial institutions underlines the broader impact of the crisis related to fentanyl, an opioid that has been at the center of a nationwide epidemic in the U.S., leading to significant enforcement actions and policy shifts.