Customs officials in Malmö found 40 semi-automatic weapons concealed in the seats of a car on October 10th last year.
The driver of the vehicle was pulled over after customs officials noticed him behaving in a nervous manner when crossing the border from Denmark to Sweden.
One of the driver’s two passengers was also arrested. A woman travelling in the car was released almost immediately.
A criminal investigation conducted by the customs authorities also led to the identification of two further suspects.
“Cooperation on the international and national levels has worked extremely well,” said Rolf Bårdskär, head of Swedish Customs’ investigative division.
The customs authority has described the haul as one of the largest weapons seizures ever made in Europe.
The four suspects, each with addresses in southern Sweden, have been indicted on arms trafficking charges.
Both men arrested at the Lernacken border station in Malmö admit to smuggling Beretta and Zastava weapons from Kosovo to Sweden. The two suspects arrested later deny committing an offence.