MADRID: The suspects were detained by officers from the Central Bureau of Police Investigation (CBŚP) based in Szczecin, north-west Poland.
The bureau said officers found clues about the activities of an organized crime gang in early 2016. A probe found the gang was smuggling drugs from Spain to Poland, where they were sold.
The money is believed to have been sent abroad and then laundered. Police seized drugs including marijuana, amphetamines, ecstasy tablets and LSD.
The suspects were also found to have three pistols, a rifle and live ammunition.
