Three Mexican nationals tied to cross-border trucking companies were charged Tuesday in San Diego federal court following the discovery of a massive cache of drugs, cash and ammunitions stockpiled at an Otay Mesa truck yard, the U.S.

This collection belonged to the Sinaloa Cartel, authorities said.

The case is part of a much broader investigation into the cartel’s activities, a probe that began nearly a decade ago in San Diego County and has resulted in charges against more than 125 people, many of them leaders in the inner circle of the organization.

One thread led investigators to a pair of brothers, Jorge Alberto Valenzuela Valenzuela and Gabriel Valenzuela Valenzuela, identified as high-ranking members who together own multiple Mexican trucking companies that they use to transport cocaine from Sinaloa, Mexico, into the U.S., according to an arrest affidavit.

But the pilot inspected the contents of one piece of luggage, discovering what appeared to be bricks of drugs wrapped in plastic, according to the affidavit.

The agency worked jointly with the Drug Enforcement Administration, the San Diego Police Department and Sheriff’s Department and the U.S.

Among those who took guilty pleas were Dámaso López-Serrano, a godson of Sinaloa cartel kingpin Joaquín “El Chapo” Guzmán; Jose Rodrigo Arechiga Gamboa, who led the cartel’s assassin squad as “El Chino Antrax”; and Serafin Zambada Ortiz, a U.S.

citizen born in San Diego who is a son of the cartel’s at-large co-leader, Ismael “El Mayo” Zambada.

Last week, a former Mexican federal police officer alleged to be a high-ranking member, Ramón Santoyo Cristóbal, was extradited to San Diego following an arrest last year in Rome on a 2016 warrant.