The U.S. Justice Department on Tuesday accused Chinese "underground bankers" of helping Mexico's Sinaloa Cartel launder more than $50 million in drug trafficking proceeds.

An indictment unsealed in California charged 24 defendants with conspiracy to distribute cocaine and methamphetamine and money laundering offenses.

Drug Enforcement Administration (DEA) chief Anne Milgram said a multi-year investigation dubbed "Operation Fortune Runner" had "uncovered a partnership between Sinaloa Cartel associates and a Chinese criminal syndicate operating in Los Angeles and China to launder drug money."