The ship was attacked just about 100 miles off Nigeria’s coast.
The incident occurred late on the 25th April.
A Polish and a Russian citizen were among those taken hostage.
Maritime insurance costs are said to be increasing due to growing trends in attacks in the Gulf of Guinea.
14 heavily armed pirates hijacked the ship accessing its citadel according to The International Maritime Bureau (IMB).
They managed to access the purposely-designed strong room to protect crew from attack.
Five of the crew were kidnapped and an amount of cash was taken.
The IMB have said that pirates off Nigeria had chased and fired at another ship the previous day.
The vessel however increased speed and escaped attack.
Many vessels have little protection making them an easy target however Naval patrols and the appearance of armed guards has helped reduce piracy off Somalia.
