On Monday, HUR reported that Sparta had broken with Portugal, but that the problem had been fixed. Ursa Major was also known as Sparta III, so it was unclear which ship this was referring to.
It is not known what caused the explosion on Ursa Major as it passed between Oran in Algeria and the Spanish city of Aguilas.
However, video taken from the Ross Sea tanker between 12:00 and 13:00 GMT on Monday and confirmed by the BBC showed the ship mismaneuvering.
It eventually sank at about 01:20 GMT on Tuesday.
The Big Dipper was built in 2009 and has come under sanctions following Russia’s full-scale invasion of Ukraine in 2022 because of the shipowner’s role in delivering cargo to the Russian military.
Oboronlogistika said the cargo ship, which it called the flagship of its fleet, was carrying 45-tonne hatches for icebreakers as well as large cranes for the Vladivostok port.
