The loaded vessel, the Nave Constellation, was attacked 77 nautical miles off Bonny Island on Tuesday and 18 Indians and one Turk from the crew were seized, the official said.
Seven other crew members remain on board the vessel. Neither the vessel nor the cargo were damaged, the official said.
The shipping industry has warned in recent months about the increasing dangers faced by seafarers in the Gulf of Guinea, particularly around Nigeria, including kidnappings by pirates.
The International Maritime Bureau said in October the Gulf of Guinea accounted for more than four fifths of crew kidnappings globally.
Maritime security officials say that over the past year there has been a growing shift by pirate gangs in the Gulf of Guinea and especially Nigeria toward kidnapping crews rather than stealing cargoes, to try to extort ransom from ship owners.
The head of Nigeria’s Maritime Administration and Safety Agency Dakuku Peterside, said authorities were working to ensure the crew are secured and those abducted, released. He said the vessel owners had operated for 10 days in Nigerian waters without contacting harbor masters or Nigerian authorities.
The Hong Kong-flagged supertanker, capable of carrying up to 2 million barrels of oil, is operated by Greek shipping company Navios Tankers Management.
“We are doing everything necessary to make sure that the 19 crew members will return safe,” the official at Navios said, adding that their families have been informed.
An Indian government source said its mission in Nigeria had taken up the matter of the kidnappings with the Nigerian government and security agencies.
The vessel was carrying crude for Indian refiner Hindustan Petroleum Corp, a source at the company said.
The vessel was chartered by French oil company Total to deliver Bonny Light oil at Vizag in southern India, the source said. “Total has told us it would arrange alternative crew to get the cargo delivered on time,” the source, who did not wish to be identified, told Reuters.
In a statement sent to Reuters, Total confirmed the piracy act. “The vessel is chartered by a Total shipping entity. Crew management and nautical operations are managed by the shipowner and technical operator of the vessel,” it said.
Nigerian Navy commander Captain Kolawole Oguntuga said the vessel, which loaded Shell Bonny Light, was hijacked soon after leaving the terminal. The ship did not request a navy escort to provide them with adequate protection, he said.
Reporting by Renee Maltezou in ATHENS, Jonathan Saul in LONDON, Nidhi Verma and Devjyot Ghoshal in NEW DELHI, Tife Owolabi and Camillus Eboh in Nigeria and Bate Felix in PARIS, Editing by Alison Williams, Angus MacSwan, Christina Fincher, William Maclean