The unnamed vessel was spotted by a Dutch naval forces helicopter on Christmas Day. It was seized the next day and escorted to Santo Domingo in Dominican Republic by the US Coast Guard.
“Following a thorough inspection, the officials located 1,600 kilos of cocaine hidden between the fuel tanks aboard the ship on December 31,” the World Maritime News website reported.
Tanzania has in the past been on the spot over vessels from countries targeted by UN sanctions flying its flag, mainly North Korea and Iranian ships. It has also suffered diplomatic embarrassment after vessels it has flagged are used to ferry illicit drugs.
Officials from the ministry of Foreign Affairs were also not available for comment.
Last year, Tanzania was forced to deregister 45 foreign vessels for breach of U.N. sanctions against North Korea.
The ship seized last week, its crew and cocaine haul were handed over to the Dominican authorities for further investigation, said the maritime news site.