This is the dramatic moment police caught a narco-sub carrying almost a tonne of cocaine.

Spanish authorities, in a joint operation involving the Tax Agency, Civil Guard, and National Police, intercepted the semi-submersible vessel destined for the Iberian Peninsula in the Atlantic Ocean.

Customs Surveillance Service aboard the vessel 'Fulmar' arrested four Colombian nationals who were rescued after sinking the vessel 280 nautical miles west of the coast of Cadiz on June 25.

Officials said the vessel in question bears striking similarities to previous narco-submarines intercepted in similar operations, leading investigators to suspect it was transporting cocaine.

The operation began on June 24 based on intelligence from the U.S. Drug Enforcement Administration (DEA) suggesting a potential transhipment point involving an unidentified target and a presumably semi-rigid boat.

The Customs Surveillance Service had already intensified satellite surveillance in the area and dispatched the 'Fulmar' to intercept the vessel.

Early on June 25, approximately 280 nautical miles west of Cádiz, the Fulmar spotted a 20-metre semi-submersible vessel resembling those previously discovered in Aldan in 2019 and Arousa in 2023.

Upon seeing the authorities approach, the vessel's crew opened the bottom valves and surfaced to safety. Within minutes, the semi-submersible flooded and sank along with its cargo. The four Colombian crew members were rescued and subsequently arrested.

In a parallel operation, Spanish authorities, with international collaboration from the UK's National Crime Agency (NCA) and the U.S. DEA, seized 900 kilos of cocaine 200 nautical miles off the coast of the Canary Islands.

Spain's Ministry of the Interior said: 'The successful interception underscores the effectiveness of international cooperation and intelligence sharing in combating maritime drug trafficking in the Atlantic.'