Almost 200 sanctioned Russia-linked ships have entered UK waters despite warning

One sanctioned oil tanker - Universal - appears to have been escorted by a Russian warship, based on satellite images obtained by BBC Verify.

By matching vessel dimensions and other reports, including one by the Telegraph, experts from the intelligence firm MAIAR concluded the warship was highly likely to be the Russian frigate Admiral Grigorovich.

Ship-tracking data shows the tanker entered UK waters in the early hours of 8 April before transiting the Channel.

Alessio Patalano, professor of war and strategy at King's College London, said the fact the tanker had been escorted by a warship suggested the UK was "keeping the Russians under pressure".

The Kremlin has criticised the UK's threat to detain Russian vessels calling it "another deeply hostile step directed at Russia" and warned such actions "have consequences".

It is possible legal constraints may be preventing the UK from actively boarding and seizing tankers, said James M Turner KC, a shipping lawyer at Quadrant Chambers.

"The position with very few exceptions is that you can't seize vessels that are flying the flag of another country," he told BBC Verify.

Turner explained that if a ship travels through UK waters under a flag it is entitled to fly then there is "very little" a coastal state can do - regardless of whether the vessel has been sanctioned or is carrying sanctioned goods.

"I am wondering how this policy was formulated. It will have been carefully vetted and lawyered but it is incapable of being applied unless a tanker is false-flagged or has no flag.

"This is a case where rhetoric and reality do not coincide".

A "falsely-flagged" ship is one that incorrectly reports it is registered to a certain flag state. This is often used to help conceal the ship's true identity.

The tracking data also reveals several ships - including an oil tanker called the Yi Tong - changing their usual travel pattern.

Yi Tong is registered to a Chinese company called Pacific Shipmanagement based in the eastern province of Shandong.

In 2025, the ship travelled to and from the Port of Ust-Luga in north-west Russia to China via the English Channel.

Last month, however, the Yi Tong took a longer route around Ireland and the north of Scotland - avoiding the Channel and the UK's territorial waters.

The re-routing suggests the UK's policy is having some impact, added Prof Patalano.

"The Russians are probably already thinking how to test the UK more, and we should expect ships taking a longer route bringing some measure of challenge to UK defences and infrastructure."

Longer journeys use additional fuel, making it more costly and time-consuming for those involved in the sale of the ships' cargo.

BBC Verify asked the MoD if the UK's armed forces had intercepted any sanctioned vessels since 25 March.

The MoD did not answer our question directly but said it was "disrupting and deterring" the shadow fleet and more than 700 suspected vessels had been challenged since October 2024.

It added it would not comment on specific operations "as this could compromise our ability to successfully take action against these ships".

We went back to the MoD to ask what it meant by "challenging" vessels, but it did not provide us with further details.

Graphics by Sally Nicholls

Additional reporting by Nicholas Barrett and Yi Ma

What do you want BBC Verify to investigate?

Graphics by Sally Nicholls

Additional reporting by Nicholas Barrett

What do you want BBC Verify to investigate?