Previously vessels would be sunk once they had completed their cargo runs from South America to Europe

The plummeting price of cocaine is forcing drug-traffickers to reuse the “narco-submarines” they would previously have scuttled once the custom-built vessels had completed their cargo runs from South America to Europe, according to a senior Spanish police officer.

While semi-submersible vehicles have been used regularly in Colombia and other parts of South and Central America since the 1980s, they were not detected in European waters until 2006, when an abandoned sub was found in an estuary in the north-west Spanish region of Galicia.