Spanish police said Tuesday they had broken up an international drug-smuggling ring, seizing four tonnes of cocaine and arresting 28 people.

Spanish police said they  have busted the biggest drug-smuggling organisation in the northwestern region of Galicia
Spanish police said they have busted the biggest drug-smuggling organisation in the northwestern region of Galicia AFP / MIGUEL RIOPA

The gang, which was made up of "experienced sailors and known traffickers", was working with major national and international drug smugglers to "bring in cocaine shipments by sea", a police statement said.

Spanish authorities boarded the MV Karar and found that it was carrying 4000 kgs of cocaine
Spanish authorities boarded the MV Karar and found that it was carrying 4000 kgs of cocaine AFP / MIGUEL RIOPA

Police said it was the biggest drug-smuggling organisation in the northwestern region of Galicia, and had "a large number of boats and speedboats" stowed away at different locations between northern Portugal and the port city of Pontevedra.

With support from the US Drug Enforcement Agency, Britain's National Crime Agency and the Colombian police, Spanish investigators discovered that the traffickers were poised to receive a shipment and started looking for "the mothership" which they intercepted some 200 nautical miles off the coast.

Spanish police arrested all 15 crew members of the Togo-flagged MV Karar, which had been at sea for nearly three weeks
Spanish police arrested all 15 crew members of the Togo-flagged MV Karar, which had been at sea for nearly three weeks AFP / MIGUEL RIOPA

On board the Togo-flagged vessel, which had been at sea for nearly three weeks, they found the cocaine and arrested its 15-strong crew, most of whom were Bangladeshi or Nepalese.

At the same time, police raided 20 addresses in Galicia, arresting another 13 suspects, some of whom has previous convictions for drug smuggling.

Galicia's rugged Atlantic coast with hundreds of hidden coves, inlets and desolate beaches has for years been the gateway for illegal drugs to reach Europe.

In November, police intercepted a 20-metre (65-foot) submarine off the Galician coast which was carrying three tonnes of cocaine worth 100 million euros ($110 million), the first time a "narco submarine" had been found in Europe.