A Nato official has previously told BBC Verify that the Russian warship, Admiral Grigorovich, has been assigned to escort sanctioned oil tankers. But it is unclear whether the frigate is accompanying the Forwarder.
Admiral Grigorovich was involved in an incident on Tuesday when it fired warning shots towards a British yacht that had apparently moved towards it in the Channel.
A Nato official told BBC Verify that, as of Wednesday evening, Admiral Grigorovich had not moved far from the location of the incident.
In March, UK Prime Minister Sir Keir Starmer announced that British armed forces “are now able to board sanctioned vessels that are passing through our waters” which were not operating in accordance with international law. But experts told BBC Verify it was unlikely the UK or France would seek to intercept the tanker.
“Going after vessels that are falsely flagged or misusing a flag of convenience is one thing, but this would be going after Russia directly which would be a further step up in escalation,” said Frederik Van Lokeren, a former Belgian naval officer and maritime analyst.
“Since this is a Russian-flagged vessel, possibly escorted by a Russian warship, I don’t expect the UK, or any other Western country, to attempt to board her,” Van Lokeren said.
The Smyrtos was boarded and seized by Royal Marines and officers from the National Crime Agency (NCA) as it was sailing without a registered flag in breach of international law. The ship is currently being held by UK officials off the coast of Weymouth and its captain has been charged with contravening sanctions.
Mark Douglas, an analyst with Starboard Maritime Intelligence, also noted that the circumstances surrounding the Smyrtos had provided a much clearer legal basis for the UK to board the vessel.
“Give that the Cameroon registry had delisted Smyrtos before she sailed through the Channel there were definitely reasonable grounds to suspect the vessel was without nationality,” he said.
“Forwarder, on the other hand, is flagged by Russia and despite the opaque ownership structure we have no information to suggest that is a false flag.”
An MoD spokesperson told BBC Verify: “Any target ship will be individually considered by law enforcement, military and energy market specialists before an operation is executed.”
In the aftermath of the boarding of Smyrtos, ship-tracking data showed multiple sanctioned tankers altered their course to avoid the English Channel. Many sanctioned vessels currently appear to be taking an alternate route around the west coast of Ireland.
