$45 Million In Cocaine Seized After Secret US-Mexico Tunnel Discovery

Federal agents investigating a suspected cross-border tunnel between Mexico and the United States disclosed that they have uncovered a drug trafficking operation that allegedly moved more than $45 million (£35.5 million) worth of cocaine through the underground passage.

The discovery followed a months-long investigation that culminated in the seizure of more than a ton of cocaine and the arrest of four men accused of using the tunnel to smuggle drugs into the US.

Authorities affirm that the tunnel linked Tijuana to a business known as Buy 4 Less in San Diego's Otay Mesa neighbourhood, just north of one of the country's busiest border crossings. Investigators said the passageway was far more advanced than a simple underground route, featuring lighting, ventilation, and an electronic transport system designed to move items between the two countries.

The case has since led to multiple federal charges and prompted officials on both sides of the border to highlight the scale of the alleged operation and the cooperation involved in bringing it to an end.

Four Men Arrested Following Months-Long Investigation

According to a release issued on 1 June by federal prosecutors in Southern California, the investigation resulted in the arrest of Gregorio Epifanio Hernandez Lopez of San Diego, Brandon Escalante Sandoval of Mexico, Jose Jimenez of San Diego, and Antonio Cortez of Mexico.

Authorities said Lopez has been charged with Conspiracy to Use a Cross-Border Tunnel and Conspiracy to Import Controlled Substances. All four defendants have also been charged with Conspiracy to Distribute Controlled Substances.

A federal complaint cited in the release stated that investigators with the Homeland Security Investigations Tunnel Task Force maintained regular surveillance of the Buy 4 Less warehouse between December 2025 and May 2026 after observing what they described as suspicious activity at the location.

Authorities believe the tunnel connected Tijuana to the Buy 4 Less business in San Diego's Otay Mesa neighbourhood. During the investigation, agents uncovered evidence that led them to suspect the passageway was being used to transport large quantities of narcotics into the United States.

The operation ultimately led to the seizure of more than a ton of cocaine, with authorities estimating the value of the drugs at over $45 million (£35.5 million). Prosecutors said the arrests and seizures marked a major outcome in a case that had been developing over several months.

Sophisticated Tunnel Equipped With Lighting And Electronic Transport System

Investigators said the tunnel was fitted with operational infrastructure that allowed it to function as a highly organised trafficking route. According to authorities, the underground passage contained lighting and ventilation systems, while an electronic sliding mechanism had been installed to move items in both directions between Mexico and the United States.

Officials described the tunnel as a sophisticated operation designed to support cross-border smuggling activities. The discovery was made through intelligence work carried out by agents from Mexico's Criminal Investigation Agency, known as the FGR's Criminal Investigation Agency, working alongside Mexico's Security Cabinet.

Authorities said the search warrant connected to the tunnel was executed as part of an investigation into alleged violations of Mexico's firearms and explosives laws, as well as drug-related offences.

Kevin Murphy, acting Special Agent in Charge for HSI San Diego, said the findings represented a major development in the investigation.

'This investigation and seizure represent a significant blow to the Jalisco New Generation Cartel. 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 Homeland Security Investigations and our Homeland Security Task Force (HSTF) partners,' Murphy said.

He added: 'HSI Special Agents and task force members worked tirelessly to disrupt the flow of dangerous narcotics into our communities, and we remain steadfast in our mission to protect the public and keep our communities safe.'

San Diego County Sheriff Kelly Martinez also stressed the importance of cooperation between agencies involved in the case.

'Law enforcement collaboration is the backbone of dismantling sophisticated transnational drug cartels, as these organisations rely on vast illicit supply chains spanning multiple jurisdictions,' Martinez said.

She added that joint operations help disrupt trafficking networks, limit illicit financial activity, and prevent criminal organisations from exploiting jurisdictional gaps.

'The Sheriff's Office is grateful for the partnerships, hard work, and dedication of everyone involved in this investigation, and we will continue to support our federal partners in cases that keep our communities safe,' Martinez said.