The drugs were found in a KAMAZ lorry, which was stopped during a joint Tajik and Afghan special service operation, on the Dushanbe-Khujand highway on May 11.
"More than 423 kilograms of narcotics, including over 33 kg of heroin, was seized," Fakhriddin Dzhonmakhmadov said adding that officers had also confiscated a pistol with 15 rounds.
Experts estimate the haul is worth some $400,000 in Tajikistan and over $10 million in Europe.
The drugs originated from a region in northeast Afghanistan, the world's leading heroin producer, and were destined to be smuggled into Russia. Three people were arrested on suspicion of being involved in drug trafficking.