A drug tunnel between Arizona and Mexico was discovered under a former fast food restaurant

(CNN) — Authorities in Arizona discovered $1 million in drugs during a traffic stop — and officials say that led them to a nearly 600-foot drug tunnel that runs between a former fast food restaurant and a private home in Mexico.

It all began August 13, when police in the border city of San Luis, Arizona, say they saw the owner of a now-abandoned business bringing several plastic containers outside and loading them onto a trailer, according to court documents obtained by CNN affiliate KGUN.

Police found drugs inside containers that apparently came through the tunnel.

Officers pulled the man over for an unspecified equipment violation. During the traffic stop, a narcotics dog alerted authorities to the presence of drugs in the two containers.

Inside the containers, police found 239 packages of various drugs, including over 261 pounds of methamphetamine, 14 pounds of cocaine, 30 pounds of white heroin, 13.7 pounds of brown heroin and 6.8 pounds of fentanyl. The fentanyl alone “translates to over 3 million dosage units,” Homeland Security Special Agent Scott Brown told CNN affiliate KYMA on Wednesday.

Police listed the total value of the drugs at over $1 million.

The suspect was identified in court documents as Jesus Ivan Lopez Garcia and is facing federal charges including conspiracy to possess with intent to distribute methamphetamine and cocaine. CNN has been unable to determine if he has made his first appearance before a US Magistrate.

An aerial view of the business the tunnel was found in.

According to court documents, Lopez Garcia purchased the property in April of this year for $390,000. It used to be a Kentucky Fried Chicken restaurant. The criminal complaint filed says “the structure was vacant in recent years and was

not used for business.”

Police searched the vacant restaurant two days later and discovered the entrance to a tunnel inside, court documents said.

Homeland Security Investigations officials told KYMA that the tunnel ran 22 feet deep and traveled nearly 590 feet underground to a residence across the border in San Luis Rio Colorado, Mexico, where it ended in a trap door underneath a bed. Homeland Security did not immediately respond to a CNN request for comment.

The US-Mexico border above the tunnel is protected by two border fences, according to court documents.

Police found drugs inside containers that apparently came through the tunnel.

“This tunnel was very well constructed and would have taken this Drug Trafficking Organization a long time to dig and would have been very expensive,” court documents state. “This tunnel necessarily required a combination of several individuals on both sides of the border, engaged in an intricate, risky transnational conspiracy to construct such a secretive structure.”

Smuggling tunnels underneath the US-Mexico border have been found on occasion in the past, built by criminal organizations to traffic drugs and humans into the country.

In 2016, a drug trafficking tunnel nearly half a mile long was found running underneath the California-Mexico border. The 800-yard tunnel route began at a house in Tijuana, Mexico, and ended in the Otay Mesa neighborhood of San Diego.

In 2012, police found a “sophisticated drug smuggling tunnel” that began inside an ice plant in San Luis Rio Colorado, Mexico, and ended inside an one-story, nondescript building in San Luis, Arizona. Police learned of the tunnel after a traffic stop yielded 39 pounds of methamphetamine.