French customs have seized a luxury mega-yacht belonging to Russia's 'second most powerful person' Igor Sechin as it attempted to leave the port of La Ciotat.
The vessel was in breach of EU sanctions, Finance Minister Bruno Le Maire said.
The move came as western states are implementing massive sanctions, including asset freezes, against Russia for invading its neighbour Ukraine.
The incredible ship is valued at £86m, according to VesselsValue.
Mr Sechin is a long-term ally of Russian President Vladimir Putin, and was in 2017 described as the second most powerful man in Russia.
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A separate near-$600 million luxury yacht owned by Russian billionaire Alisher Usmanov has also been seized, by German authorities, Forbes reported.
The Dilbar, which Mr Usmanov purchased in 2016, has the largest swimming pool ever installed on a yacht.
The 88-metre "Amore Vero" arrived in La Ciotat on Jan 3 and was due to stay there until April 1st for repairs, the finance ministry said in a statement, adding that the vessel was subject to the new sanctions.
But on Wednesday, customs officers noted the yacht was "taking steps to sail off urgently, without the repair works being over," the statement said, adding that the officers therefore decided to seize it.
The finance ministry said the yacht belongs to a company whose main shareholder is Sechin, a close ally of Russian President Vladimir Putin.
The superyacht was built by Oceanco in the Netherlands and delivered to its owner in 2013, according to yachtcharterfleet.com.
It says its onboard features include a beauty salon and gym. It sails under the flag of the Cayman islands, according to Eikon data.
"Thank you to the French customs officers who are enforcing the European Union's sanctions against those close to the Russian government", Finance Minister Bruno Le Maire said in a Tweet.
At least five other superyachts owned by Russian billionaires have arrived in the Maldives, according to ship tracking data.
Separately, French authorities on Thursday also seized a Russian-owned cargo vessel in the port of Lorient, Brittany.
The Russian invasion of Ukraine will get worse as major cities come under more indiscriminate bombing, French President Emmanuel Macron fears following a phone call with Vladimir Putin.
The warning came during a day of continued attacks on cities including Kyiv and Kharkiv, which have suffered intense damage.
Attempts to seize both cities have failed so Kremlin forces have instead resorted to heavy bombing, causing thousands of civilian casualties.
