Mexico cops discover massive tunnel into America from Tijuana — and it was hidden in plain sight

Cops on both sides of the US-Mexico border are investigating a sprawling underground passage uncovered in the Tijuana area that is believed to extend toward the US.

The tunnel was found Saturday in the Nueva Tijuana neighborhood during a raid carried out by Mexican federal authorities with support from the Mexican Navy, according to Mexico’s Attorney General’s Office.

Investigators said the hidden passage stretches roughly 869 feet and sits about 21 feet below ground, making it one of the more substantial cross-border tunnel discoveries in recent years.

The underground route was uncovered after authorities executed a search warrant at a property in eastern Tijuana.

During the operation, officers seized a variety of items, including ammunition, cell phones, bank cards, a digital video recorder and dozens of doses of methamphetamine.

While inspecting the site, investigators located a wooden-lined tunnel that officials believe was constructed to reach the U.S. border.

Mexican authorities said evidence recovered during the raid suggests the property may have been used as a logistical center for criminal activity, including the storage and movement of narcotics, weapons and explosive materials.

Following the search, both the seized evidence and the property were transferred to federal prosecutors, who are continuing the investigation.

The discovery has also drawn the attention of U.S. authorities.

In a statement, Homeland Security Investigations confirmed agents are participating in an active probe involving the underground passage near Otay Mesa, a major border crossing area between Tijuana and San Diego.

“Special Agents with Homeland Security Investigations (HSI) in San Diego, in coordination with our Homeland Security Task Force (HSTF) partners, are conducting a criminal enforcement operation involving a cross-border subterranean tunnel in Otay Mesa, CA.

“To protect the integrity of the ongoing investigation and ensure the safety of all involved, we are unable provide additional details at this time.”

Officials have not yet disclosed where the tunnel may emerge on the U.S. side of the border, how long it may have been in operation, or whether any arrests have been made in connection with the discovery.

Cross-border tunnels have long been used by transnational criminal organizations to move drugs, cash and other contraband between Mexico and the United States while avoiding heavily monitored ports of entry and border security infrastructure.