Medallion Marine, a Mumbai-based shipping firm, said the hostages were freed in good health, but did not disclose whether a ransom had been paid, or whether Nigeria’s security forces played any role in securing their release.
Kidnap for ransom is common in Nigeria’s southern oil producing Niger Delta region, with expatriate workers often being targeted, but the companies involved rarely comment on ransom demands.
Nigeria’s navy spokesman could not immediately be reached to comment on the circumstances of this release.
“The five crew members who were taken from the (MT SP Brussels) vessel by armed men off the Niger Delta in December have been released,” a company statement said.
“Following medical examinations, the crew members have now been flown home in order to be reunited with their families,” it added.
After the December 17 attack, a company spokesman told AFP that all five people kidnapped were Indian nationals.
A 2009 amnesty deal with rebel groups in the Niger Delta significantly reduced such kidnappings, but they still occur both onshore and in the Gulf of Guinea, which includes the waters off Benin and Togo, as well as Nigeria.
Noel Choong, head of the International Maritime Bureau’s piracy reporting centre in Kuala Lumpur, told AFP last month that there were 51 kidnappings in the gulf in 2012, making it one of the most dangerous areas for seafarers after Somalia.
The IMB has also reported that attacks in west African waters have grown increasingly violent in recent years, with pirates frequently firing on the vessel they seek to board.
The theft of fuel cargo for sale on the region’s lucrative black market is also considered a key motivation for such attacks, aside from ransom payment.
Three Italian sailors seized from a ship in the Niger Delta two days before Christmas were released on January 9.
Nigeria is Africa’s largest oil producer and the continent’s most populous nation with some 160 million people. The Niger Delta region remains deeply impoverished despite its oil reserves, with corruption rampant.
Violent abductions have also occurred in the north of the country, but those attacks, blamed on radical Islamist groups, are considered a different phenomenon from the unrest in the Niger Delta.
Islamist extremists are suspected of having abducted British, Italian, German and French hostages.