11:53 GMT
Kayleen Devlin
BBC Verify senior journalist
The Marinera tanker reportedly being pursued by US forces changed the flag under which it was registered from Guyana to Russia mid-voyage on 24 December.
As we reported yesterday, several other sanctioned tankers have made similar registry changes to Russia in recent weeks. Michelle Bockmann, a maritime intelligence analyst at Windward, says vessels do sometimes change their flag mid-voyage but that “it’s highly unusual and only seen with dark fleet tankers”.
Brockman told BBC Verify that changing ship’s flag to a Russian registry can “complicate US enforcement efforts”.
The US Coast Guard tried to board Marinera/Bella 1 last month in the Caribbean when it was believed to be heading towards Venezuela. It was on a list of tankers under US sanctions.
Brockman added: “With Marinera, it was previously flying falsely under the flag of Guyana. Under United Nations Convention of the Law of the Sea, there’s a provision called Article 110 that allows a stateless vessel to be boarded by authorities. By reflagging to Russia, the vessel is no longer able to be boarded under this provision.”
Since the US seizure of Skipper on 10 December – the first oil tanker seized by the US Coastguard – BBC Verify has identified a total of 18 US-sanctioned oil tankers that switched to a Russian registry, with many of them having previously been sailing under a false flag.