According to the Portuguese government, the MSC Aries is “owned by the Zodiac Maritime Limited company”, which it said is based in London.
The company is owned by an Israeli billionaire.
“There is no record of Portuguese citizens on board, whether crew or command,” the statement said.
The number of those on board has not been released.
Mediterranean Shipping Company confirmed the seizure, telling CNN there are 25 crew on board.
The naval forces of Iran’s Islamic Revolution Guards Corps (IRGC) seized the container ship in a “helicopter operation near the Strait of Hormuz”, state news agency IRNA reported on Saturday, which added the vessel was being taken to Iranian waters.