SAN DIEGO — Over $4 million worth of cocaine was seized by U.S. Customs and Border Protection last week after the drugs were found in a shipment of decorative stone, the agency said Wednesday.

Officials encountered the shipment at 10:30 p.m. Jan. 11 during an examination of a tractor-trailer that entered at the Tecate Cargo Facility with a load of what appeared to be stone used for landscaping, CBP said in a news release.

According to the account from officials, CBP officers randomly removed one of the rocks from the trailer, noting an anomaly. A K-9 team then screened the shipment, alerting officials of the drugs concealed in a plaster-like material made to look like stone.

Fifty-seven cellophane-wrapped packages of cocaine were discovered in the shipment, weighing approximately 256 pounds and worth about $4.1 million, according to the estimated street value given by CBP.

The 36-year-old driver, a Mexican citizen, was detained on suspicion of attempting to smuggle narcotics and was placed in custody of Homeland Security Investigations with U.S. Immigration and Customs Enforcement.

View data on CPB enforcement actions here

According to CBP data, as of Jan. 6, about 561,291 entry encounters have been made at all 300 entry checkpoints since October. Of those encounters, about 2,755 drug seizures have been made, confiscating narcotics like cocaine, fentanyl and marijuana.