Border agents seized 515 pounds of cocaine from a flatbed trailer crossing Laredo’s World Trade Bridge from Mexico, U.S. Customs and Border Protection officials said Dec. 17.

The seizure occurred after an officer asked the driver of a tractor-trailer to pass through a drive-through scanner. The scanner picked up odd shapes, and a drug-sniffing dog alerted officers to the scent of cocaine in the tires, The Associated Press reported.

The cocaine has a street value of $8.2 million, officials said.

The cocaine, tractor and trailer were seized. The driver was not arrested, and an investigation is continuing.