The Bulgarian Customs Headquarters said that customs inspectors found the drugs in a car at the Kapitan Andreevo border checkpoint on August 9.
A press release issued the same day said the heroin was travelling from Istanbul to Bosnia and Herzegovina.
The heroin’s estimated street value is more than 1.5 million dollars.
It was hidden in 23 packages in the car’s gasoline tank. The car was driven by a 44-year-old Bosnian national.