The goods are believed to have passed through several countries and were to end up in Greece, according to the authorities.
Record seizure in the port of Burgas, Bulgaria: 436 kilograms of heroin, placed in 434 packages, with an estimated value of nearly 35 million euros were found in a cargo trailer.
This is the largest amount of narcotic substances seized in the territory, according to district prosecutor Georgi Chinev.
So far, no arrests have been made and no potential accomplices have been identified.
The seized semi-trailer arrived in Bulgaria by ferry from Georgia. But the cargo had passed through several countries beforehand.
According to local authorities, the heroin was supposed to pass through Bulgaria and end up in Greece.