The operation, named Eclipse/Hawara, was carried out by Portugal's Polícia Judiciária (PJ) together with Spain's National Police.

In total, authorities seized 3.35 tonnes of cocaine, three firearms and two vehicles, while three men were arrested in Portugal and Spain.

The Polícia Judiciária said the investigation uncovered a network suspected of bringing large quantities of cocaine from Latin America into Europe.

The organisation allegedly used high-speed boats to collect cocaine transferred from larger "mother ships" at strategic locations in the Atlantic Ocean. The drugs were then brought into Portugal before continuing towards their final destination in the Costa del Sol area of southern Spain.

One of the arrests took place in Portugal with the support of the GNR's Évora traffic unit.

A 37-year-old foreign national was stopped while driving a vehicle carrying 1,530 kilograms of cocaine. Police also found two loaded automatic weapons, which the PJ said were ready to use.

The man was arrested at the scene and later appeared before a judicial authority, which ordered him to remain in preventive detention.

The investigation involved close cooperation between Portuguese and Spanish authorities, which shared information about the group's methods and followed the movements of suspects from the arrival of the drugs through to their intended destination.

Spanish authorities also carried out arrests as part of the operation. The investigation led police to the Costa del Sol, where the organisation was believed to be preparing the cocaine for further distribution.

The Polícia Judiciária said the investigation remains ongoing.