The tunnel is over 500 meters long and runs between Tijuana and Otay Mesa in San Diego, California.
In the same area, more than a dozen other tunnels have been discovered in the last 20 years, as the muddy soil is favorable to dig in.
Six people have been arrested and the police have seized 799 kilos of cocaine, 75 kilos of methamphetamine, 1.5 kilos of heroin and over 1,200 kilos of marijuana.
The estimated street value of the drugs is SEK 300 million.
- I am very happy to be able to report that there is no light at the end of this drug tunnel, says lawyer Randy Grossman.
- We will stop all underground smuggling routes we find to prevent illegal drugs from reaching our streets and destroying our families and communities.
It is unclear how long the tunnel has been used.
Under U.S. federal law, authorities must fill entrances to tunnels that are discovered with concrete.