The Panama-registered MT Marine Express, loaded with 13,500 tons of petrol, had been anchored off the Benin City of Cotonou before authorities lost contact with the vessel on Thursday.
“Our mission in Abuja (Nigeria) is in touch with the authorities in Benin and Nigeria for their help in locating the ship and is constantly monitoring the situation,” Indian Foreign Ministry spokesman Raveesh Kumar said Sunday.
The Hong Kong-based Anglo-Eastern shipping company, which manages the tanker, said the last contact with the crew was made on Thursday.
“Authorities have been alerted and are responding. Our top priority is the safety of the crew, whose families have been contacted,” it said on Twitter.
According to AFP, local media reports said it was the second ship to go missing from the area in the last month.
In January, MT Barret went missing, but the crew, most of them Indians, were released six days later after reportedly paying a ransom.
Several ships have been targeted by pirates in the Gulf of Guinea, seriously disrupting the international shipping route and costing the global economy billions of dollars.