After weeks of investigation, Italian authorities announced late Friday that they had impounded a nearly $700 million superyacht, saying that its owner had “significant economic and business links” to “prominent elements of the Russian government.” According to U.S. officials, the prominent element is none other than Russian President Vladimir Putin.

In recent days, the Scheherazade, as the enormous luxury ship is named, showed signs of readying to set sail, apparently aiming to leave before the Italian government could seize it. But late Friday, Italian police boarded the yacht — which is 459 feet long, with two helicopter decks, a gym and a swimming pool convertible into a dance floor — and told the crew that the ship was not going anywhere. The Italian finance ministry announced that an investigation had established that the ship’s owner, whom it did not name, was an individual that “threatened peace and international security” and that the individual’s actions amounted to the “undermining or threatening the territorial integrity, sovereignty and independence of Ukraine.”

The ministry also specified the urgency to implement the restrictions as the reason to freeze the floating, and expensive, asset.

Italian authorities, who have impounded villas and yachts belonging to sanctioned Russian oligarchs, said in a statement that they had impounded the ship, which is in dry dock in the port of Marina di Carrara, on the northern coast of Tuscany, even though the person they had identified as its technical owner did not appear on a European sanctions list. They added that they could not name the individual until the European Council published the name, and the Italian government committee tasked with protecting the country’s financial security called for the person’s name to be added to the list.

Italian media outlets have for weeks reported that Eduard Khudainatov, a Russian oil tycoon who is not under sanctions, owns the yacht. Khudainatov is considered close to Igor Sechin, a powerful oligarch and close friend of Putin’s who is under sanctions. Italian financial police officials reached Friday night declined to say who they believed owned the ship.

The captain and the chair of the Marina di Carrara shipyard, where the Scheherazade underwent refitting and has wintered for two consecutive years, have denied assertions made by U.S. intelligence services, construction workers, crew members and locals in the small port that the vessel unofficially belongs to, and is for the use of, Putin. They have argued that, on paper, it belonged to a Russian individual who hasn’t been sanctioned by international authorities.

The ship’s captain, Guy Bennett-Pearce, told The New York Times recently that its owner was not on the sanctions list, but also denied having seen or met Putin on the yacht.

Yet a former Scheherazade crew member told the Times that he had never heard of Khudainatov and confirmed that crew members always believed the real owner to be Putin.

This article originally appeared in The New York Times.