Authorities investigated the network -- members of which had attempted to cover their tracks by setting up legitimate businesses -- for more than a year, according to a statement from Spain's national police on Monday.
The investigation culminated in the arrests and the seizure of 2,065 kilograms (2.28 US tons) hidden in a shipment of 40,000 kilograms (44.1 US tons) of charcoal at the port of Algeciras in southern Spain.
At the beginning of 2020, police identified members of the organization based in the provinces of Murcia and Seville who were building an apparently legitimate business importing dozens of containers of charcoal from South America to the port of Barcelona.
However, complications due to storage issues and the coronavirus pandemic meant the group moved their operations to the port of Algeciras in southern Spain in mid-April, said police.
Police pieced together the structure of the network, which included two families with key members in Brazil and Paraguay who coordinated cocaine shipments, while others in Seville created businesses which appeared to be dedicated to importing charcoal, rice, molasses or medical products.