The Mexican soccer star Rafael Márquez and several of his businesses have acted as fronts and held assets for a major drug trafficking organization, according to the United States Treasury Department.

On Wednesday, Márquez, who plays for the Mexican club Atlas and has represented Mexico at the last four World Cups, was placed on a Specially Designated Nationals list by the Treasury Department’s Office of Foreign Assets Control.

Márquez’s soccer school, his charitable foundation and 21 other individuals and 41 entities were added to the list by the Treasury Department; all were accused of providing support to, or being under the control of, another Mexican national, Raul Flores Hernandez, and what the department called the “Flores drug trafficking organization.”

The Foreign Narcotics Kingpin Designation Act, better known as the Kingpin Act, was passed by Congress in 1999, and allows the Treasury Department to freeze the assets of foreign nationals it believes to be involved in international narcotics trafficking and to prosecute Americans who handle drug trafficking money. According to a Treasury Department news release announcing Wednesday’s actions, all of Márquez’s assets “that are under U.S. jurisdiction or are in the control of U.S. persons” have been frozen.

In addition to having assets frozen, once an individual or entity is designated as a specially designated national, according to the Treasury Department’s description of the list, “U.S. Persons are generally prohibited from dealing with them.”

The United States sees the act as an important tool to clamp down on the finances of organized crime and drug trafficking groups, and to expose the vast web of dummy businesses that allow criminals to obscure and launder their ill-gotten gains. But defense lawyers and some people named to the list — which now totals more than 2,000 individuals and entities — have complained that it is rife with errors, and tarnishes reputations with scant evidence and no due process.

Márquez, 38, is one of the greatest Mexican soccer players. A center back and defensive midfielder, he has appeared for his national team 142 times over the last 21 years, and was captain of Mexico’s team at each of the last four World Cups. His club career took him to Europe, where he won four league titles and two Champions League trophies while playing for Barcelona, and to the United States, where he played two years with the Red Bulls of Major League Soccer.

He currently is the captain of Atlas, which is based in Guadalajara, and he remains a fixture of the country’s national team, which is likely to qualify for next summer’s World Cup in Russia.