Mexico extradited Víctor Manuel Félix, one of the alleged leaders of the powerful Sinaloa cartel, to the United States, where he faces charges.
Felix, who was arrested in October in Mexico City, appeared before a federal judge in San Diego on Tuesday, a day after arriving in California.
He is accused of coordinating the transfer of tons of cocaine and laundering millions of dollars for the cartel.
The indictment alleges that the case involves an undercover agent of the DEA, who infiltrated the criminal organisation that traffics tons of drugs into the United States and hundreds of millions of dollars in cash.
Some of that money was deposited in a bank account that the DEA operated confidentially in San Diego.
The United States had requested the extradition of Felix.