Packages of cocaine have been discovered on a Hapag-Lloyd containership that was boarded by five men off Colombia.
The German shipowner confirmed that the 4,612-teu Dusseldorf Express (built 1998) had called in authorities when crew found "pirates" on board off Cartagena on 8 January.
The seafarers retreated to the citadel and the men were removed.
Now, it has emerged that coastguard units and police also seized 1,539 kg of cocaine discovered on the vessel.
El Universal reported that the operation took place nine nautical miles (16 km) from shore.
The vessel was bound for Morocco.
"The result was produced thanks to a timely call by the ship's crew, who alerted the authorities to the presence of stowaways on the boat," the navy said in a press release.
"Immediately, Cartagena Coast Guard units escorted the ship to the safe dock, where, in the company of port police officers, they inspected the boat, finding 1,539 packages containing the illicit substance, stored in different containers."
Link not proven
It has not yet been proven that the gang was responsible for planting the drugs, but the navy views this as likely.
The drugs had a street value of $47m.
Security consultancy Ambrey said the boarding had occurred 40 nautical miles (74 km) offshore.
The vessel then drifted 21 nautical miles in a south-westerly direction for more than 12 hours, before proceeding 23 nautical miles north-east at 14 knots.
The ship then drifted a second time for another 10 hours.
The German vessel had earlier called at Manzanillo International Terminal (MIT) in Colon, Panama.
Hapag-Lloyd said it did not have any further information. The vessel is not directly managed by the company.
