UK seizes Russian shadow fleet tanker in English Channel

British forces boarded and seized a Russian shadow fleet oil tanker in the English Channel early Sunday, in a six-hour operation that Prime Minister Keir Starmer said showed the UK would pursue vessels accused of helping Moscow evade sanctions.

Royal Marine Commandos and specially trained National Crime Agency officers boarded the tanker Smyrtos with support from the Royal Air Force, the Ministry of Defence said. The operation was also supported by aircraft from the Maritime Air Group, an RAF P-8 aircraft, HMS Sutherland and HMS Ledbury, according to the BBC.

“This successful operation delivers yet another blow to Russia and reminds those fuelling Putin’s war in Ukraine that we will not let them hide,” Starmer said.

The Ministry of Defence said the Smyrtos would be held and monitored off England’s south coast while investigations continue. Al Jazeera reported that the vessel would be “provisionally moved to an anchorage off the South Coast of England and will be monitored for any environmental or safety concerns.”

Tracking website MarineTraffic lists the Smyrtos as sailing under a Cameroon flag and at anchor in the English Channel, the BBC reported.

The UK says Russia has used a “shadow fleet” of tankers to evade international sanctions on its oil exports after the full-scale invasion of Ukraine in 2022. The Ministry of Defence said the fleet includes more than 700 vessels and is responsible for carrying 75% of Russia’s sanctioned oil, making it a critical source of revenue for the Kremlin.

Defence Secretary Dan Jarvis praised the personnel involved. “Operations like this require skill, professionalism and courage. I pay tribute to our Armed Forces personnel and all those involved,” he said. “Russia relies on its shadow fleet to fund its conflict in Ukraine and our interdiction delivers a blow to Putin’s illegal war.”

Attorney General Richard Hermer said the operation reflected the government’s legal approach. “This government made clear that we would pursue Russia’s shadow fleet under the full force of international law,” he said.

Britain has sanctioned more than 500 vessels, according to the Ministry of Defence. The sanctions bar those ships from entering UK ports and prohibit British firms and individuals from providing financial, insurance or brokerage services to ships that supply or deliver Russian oil.

Starmer announced in March that British armed forces were “now able to board sanctioned vessels that are passing through our waters.” The government says its goal is to target Russian oil revenues and “choke off funding for Russia’s war machine” in Ukraine.

The Ministry of Defence said Sunday’s operation was conducted in close coordination with France. French President Emmanuel Macron said on June 1 that the French military had intercepted a sanctioned oil tanker suspected of being part of Russia’s shadow fleet with UK support. The Ministry of Defence told the BBC that a British helicopter provided support during that operation.

Al Jazeera reported that the French navy, with UK support, intercepted an oil tanker last month suspected of being part of the shadow fleet and falsely sailing under the Cameroonian flag, citing French authorities. It also reported that French forces impounded another suspected Russian tanker, the Grinch, in January, and detained the Deyna, which sailed from Murmansk under a Mozambican flag, in Marseille in March.

According to Al Jazeera, the UK Ministry of Defence said Russia’s oil and gas revenues declined by 24 percent in 2025 compared with the previous year. Russian President Vladimir Putin has condemned the capture of Russia-linked vessels as “piracy,” Al Jazeera reported.