A lorry carrying smuggled cigarettes worth more than €1.8m was stopped on the Struma motorway near the village of Marikostinovo in Petrich municipality, the prosecutor's office press centre said.
The driver, a 59-year-old Bulgarian, has been charged. Blagoevgrad District Prosecutor's Office is leading the case.
The tractor unit and semi-trailer, which had Bulgarian plates, was pulled over for a check at midnight on 23 October. It was coming from Greece, and its papers said it was carrying household goods.
The lorry went through an X-ray scan and a detailed customs check. Customs officers found 32 pallets, all loaded with cigarettes of a well-known brand with no excise stamps.
In all, the pallets held 480,000 packs, or 9,600,000 cigarettes.