SAN DIEGO – A 24-year-old man suspected of attempting to smuggle more than 200 pounds of fentanyl into the U.S. was charged Tuesday in federal court, authorities said.

Alexis Benito Nuno, of Tijuana, was arrested early Monday morning during a traffic stop on eastbound Interstate 8 near the Golden Acorn Casino after U.S. Border Patrol agents found 108 packages of M30 fentanyl pills hidden in the gas tank and spare tire of his 2015 Black GMC Sierra truck, according to a federal complaint. The estimated value of the drugs is approximately $3,679,000.

The reason for the traffic stop was due to a previous encounter on July 11 at a nearby checkpoint, where border agents noticed Nuno acting nervous and his truck’s gas tank showed signs of tampering, the Office of the United States Attorney Southern District of California stated in a release.

“Stopping the flow of fentanyl into the U.S. is among our highest priorities,” U.S. Attorney Randy Grossman said. “This deadly drug is fueling a public health crisis that is destroying families. It’s always a good result when fentanyl is intercepted, particularly this massive amount.”

Nuno made his first appearance in federal court Tuesday afternoon.