In early March we posted The Mystery of the Superyacht Scheherazade — Who is the Owner?. The 495′ long superyacht, valued at $700 million, was drydocked undergoing repairs in Marina di Carrara, a small Italian town on the Tuscan coast. Recently, as the yacht came off the dock and may have been making preparations to leave, it was impounded by Italian authorities.

The Washington Post reports that in announcing its action, Italy’s Finance Ministry said the yacht’s owner had “prominent” links with Russians already under European Union sanctions. The name of the owner was not specified, and Italy said only that its government had asked the E.U. to add the person to its sanctions list.

In March, an investigation by the Italian daily La Stampa named the boat’s owner as Eduard Khudainatov, a former Russian oil executive. But the newspaper also raised a question about how somebody not listed as a billionaire could afford to purchase one of the world’s most luxurious yachts.

So, speculation about the Scheherazade has only intensified. Investigators working for jailed Russian opposition politician Alexei Navalny say the yacht’s owner is Putin himself. In March, Navalny’s team published what it said was the crew list of people who had worked on the yacht. They purportedly include members of the Russian state agency responsible for Putin’s personal protection.

“We think that this is a solid enough proof that Scheherazade belongs to Putin himself and must be immediately seized,” said Maria Pevchikh, the head of the Navalny-founded FBK investigation team.