NOGALES, Ariz. - Customs and Border Protection officers say they've seized nearly 5,000 pounds of marijuana from a tractor-trailer hauling green tomatoes into Arizona.

Officers screening commercial vehicles selected the big rig for inspection at the Nogales port of entry on Dec. 30.

While the pallets of tomatoes were being unloaded, a drug detection dog alerted officers to the odor of narcotics. Several pallets with bundles of marijuana were discovered mixed in with the tomatoes.

Officers say 210 bales of marijuana weighing 4,984 pounds were seized along with the tractor and trailer.

The estimated value of the marijuana is more than $4.2 million.

The big rig's driver was an unidentified 48-year-old Mexican citizen. He was arrested and turned over to Immigration and Customs Enforcement for prosecution.