SALTON CITY, Calif. -

Border Patrol agents arrested a man Sunday afternoon after they discovered black tar heroin and methamphetamine hidden in all four tires of his truck.

Around 4:30 p.m., agents assigned to the Indio Station stopped a Chevy Silverado at the Hwy. 111 checkpoint. 

The driver was a 43-year-old citizen of Mexico who was legally in the U.S., according to a release from El Centro Sector Border Patrol.

Authorities used a backscatter X-ray system on the man's truck and discovered something abnormal with the tires. The backscatter X-ray system is similar to devices used at airports to conduct full-body scans, agents said.

When officers inspected the tires, they found several wrapped packages of black tar heroin and methamphetamine.

Agents said the heroin weighed 57.56 lbs. and is worth an estimated $575,600. The methamphetamine weighed 11.80 lbs. and is estimated at $76,700.

The suspect and the narcotics were turned over to the DEA for further investigation.