Former champion boxer Julio Cesar Chavez Jr. has been detained in Mexico after deportation by the United States to face shock charges of involvement with a drug cartel, Mexican authorities said Tuesday.

The son of boxing icon Julio Cesar Chavez stands accused of serving as a henchman for the powerful Sinaloa drug cartel, which Washington designated a foreign terrorist organization this year, and of trafficking firearms and explosives.

Acccording to Mexican media, which claim to have had access to the case files, Chavez, 39, was allegedly a “hitman” used to punish members of the cartel.

“He hangs them (and) grabs them like a punching bag,” the Reforma newspaper reported, citing testimony in the prosecutor’s documents.

The Attorney General’s Office has withheld details of the indictment.

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