In the latest global effort to crack down on Russian power brokers, the world’s largest yacht has been seized by German officials because of the vessel’s association with a sanctioned billionaire with Kremlin ties.

Through “extensive investigations,” officials were able to determine the owner of the yacht “despite offshore concealment,” the German Federal Criminal Police Office said in a tweet early Tuesday. The megaboat’s owner was determined to be Gulbakhor Ismailova, sister of Russian oligarch Alisher Usmanov, German authorities confirmed to USA TODAY.

The Office of Foreign Assets Controls “is identifying Usmanov’s superyacht and aircraft as blocked property in which Usmanov has an interest,” the U.S. Treasury Department said in an emailed statement to USA TODAY.

After police confirmed with authorities in Brussels that the owner was sanctioned, the luxury yacht, known as Dilbar, was legally commandeered. The 15,917-ton superyacht, which is hailed by its manufacturer as “one of the most complex and challenging yachts ever built,” is being held at the Port of Hamburg in Germany.

The Dilbar, named after Usmanov’s mother, is registered in the Cayman Islands and is estimated to be worth $600 million to $735 million. The vessel features two helipads and one of the world’s largest indoor pools ever housed on a yacht, according to the Treasury Department. Operating the ship takes an estimated $60 million a year.

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The Dilbar is not the first Russian yacht to be seized by the U.S. and its allies as part of sanctions against Russia for its invasion of Ukraine. At least 13 ships with a combined value of more than $2 billion are reported to have been impounded since March 2.

The seizures are part of a directive from President Joe Biden last month that the U.S. and its allies would target Russian oligarchs in response to the Kremlin’s invasion: “We are joining with our European allies to find and seize your yachts, your luxury apartments, your private jets.”

“Usmanov’s Kremlin ties enrich him and enable his luxurious lifestyle,” the Treasury Department’s statement read. The billionaire’s “vast holdings” across the Russian economy and abroad include the metal, mining, telecommunications and information technology industries, according to the department. He is known to be close to Russian President Vladimir Putin and Deputy Security Council Chairman Dmitry Medvedev.

“Usmanov and Putin allegedly have financial ties, while Medvedev has reportedly benefited from the personal use of luxurious residences controlled by Usmanov,” the department’s statement said. The billionaire also owns 49% of the holding company USM, which did not respond to USA TODAY’s request for comment.

The United States announced sanctions against Russian elites and their family members March 3 to interrupt “direct and indirect” support to the Russian government amid Putin’s invasion of Ukraine nearly two months ago. The European Union also targeted Usmanov.

“We are demonstrating our commitment to impose massive costs on Putin’s closest confidants and their family members and freeze their assets in response to the brutal attack on Ukraine,” Treasury Secretary Janet Yellen said last month in a statement announcing the sanctions.