The corridor contained a train track, power, and a ventilation system and measured 1,744 feet (531 meters).
When the find was made, US police were conducting surveillance at a residence that had previously been used as a cocaine stash house.
Cocaine, methamphetamine, and heroin were confiscated. Six persons are being held on suspicion of narcotics trafficking.
The tunnel was 61 feet (18 meters) long and 4 feet (1 meter) wide, according to the US Attorney’s Office for the Southern District of California.
Officers watched many cars arrive and go from the property in Tijuana and the warehouse on Friday, May 13th, according to prosecutors.
They were subsequently pulled over and searched, with the narcotics confiscated and arrests made.
Officers discovered the cross-border tunnel exit point dug out of the warehouse floor as they entered.
The prosecutor’s office stated that 1,762 pounds (799 kilograms) of cocaine, 164 pounds (74 kilograms) of methamphetamine, and 3.5 pounds (1.5 kilograms) of heroin had been seized.
If proven guilty, the suspects, who range in age from 31 to 55, may face a life term in jail and a $1 million punishment.
“At the end of this narco-tunnel, there is no more light,” stated US Attorney Randy Grossman.
“Every underground smuggling channel we identify will be shut down to prevent illicit narcotics from reaching our streets and hurting our families and communities.”
California’s final tunnel was discovered in 2020. That one is also the longest, with a length of 4,309ft (1,313m). There have been 90 of these sorts of secret passages identified since 1993.