Washington: Federal investigators have uncovered a sophisticated underground tunnel stretching from Mexico into Southern California and seized more than a tonne of cocaine worth an estimated $45 million, dealing what authorities described as a major blow to a powerful Mexican drug cartel. 

Four people have been charged in the case following a months-long surveillance operation that exposed the hidden smuggling route beneath a supposed retail store near the US-Mexico border.

The subterranean passageway ran from Tijuana, Mexico, to a purported retail store known as "Buy 4 Less" near the Otay Mesa Port of Entry in California. According to federal authorities, the tunnel measured about 1,933 feet in length, extended roughly 55 feet below ground and was equipped with reinforced walls, electricity, ventilation systems and a rail network.

Those charged are Gregorio Epifanio Hernandez Lopez of San Diego, Brandon Escalante Sandoval of Mexico, Jose Jimenez of San Diego and Antonio Cortez of Mexico. Hernandez Lopez faces charges of conspiracy to use a cross-border tunnel and conspiracy to import controlled substances. All four defendants are charged with conspiracy to distribute controlled substances.

"For these defendants, it wasn't a light at the end of the tunnel. It was lights and sirens," US Attorney Adam Gordon said.

The investigation was conducted by a Homeland Security Task Force that monitored activity at the Buy 4 Less warehouse from December 2025 through May 2026. Agents said the business attracted little customer traffic and appeared inconsistent with a normal retail operation. Investigators observed Hernandez and other individuals frequently moving large suitcases from the premises and engaging in other suspicious activities.

Authorities said the searches uncovered 851 packages containing a substance that field-tested positive for cocaine. The seizures included 286.2 kilograms from one truck, 469.4 kilograms from a second truck and 274 kilograms from a van, for a combined weight of approximately 1,029.6 kilograms, or more than 2,269 pounds.

"This investigation and seizure represent a significant blow to the Jalisco New Generation Cartel," said Kevin Murphy, Acting Special Agent in Charge of Homeland Security Investigations San Diego.

"The discovery and dismantlement of this sophisticated cross-border tunnel, along with the seizure of more than a ton of cocaine, underscore the commitment and collaboration of HSI and our HSTF partners."

Inside the store, investigators discovered the tunnel's exit concealed beneath the floor of a storage room. Authorities said the underground passage could be accessed using a sophisticated hydraulic lift and extended more than 1,000 feet from the store to the international border before continuing into Mexico.

"Criminal organizations continue to look for ways to exploit our border, but they underestimate the determination of the men and women protecting it," said U.S. Border Patrol San Diego Sector Chief Patrol Agent Justin De La Torre.

Officials said 99 subterranean passages have been discovered in Southern California since 1993, including 28 classified as sophisticated tunnels. The last operational tunnel discovered in the district was found in 2022.

Cross-border tunnels have become one of the most effective methods used by Mexican drug trafficking organisations to move narcotics into the United States while bypassing ports of entry and border security infrastructure. Many feature advanced engineering, including lighting, ventilation and rail systems capable of transporting large quantities of drugs.