The drugs were discovered in a vehicle in southwest Uzbekistan during a spot check, RIA Novosti reported.

At first officers discovered over 370 kilograms of heroin stashed in a metal box in the front of the vehicle. Later some 200 kilograms of the drug were found in another container.

"The vehicle was transporting cattle as a cover," the spokesperson said. The heroin could have been cut to produce almost seven metric tons of heroin, he added.

A criminal case has been opened and an investigation is underway.

About 150 metric tons of heroin and 30 metric tons of raw opium are smuggled every year through Uzbekistan from Afghanistan with 75% of the drugs sold in Russia and Western Europe, according to official reports.