(Bloomberg) -- The mystery surrounding who owns an abandoned 267-foot superyacht docked in Antigua and Barbuda deepened after lawyers for Russian billionaire Andrey Guryev said their client doesn’t own the vessel, and the government pushed ahead with plans to auction it off.

The Caribbean nation claims the Alfa Nero — a luxury yacht that sleeps 12 and has an infinity pool that turns into a helipad — belongs to Guryev, an industrial tycoon who’s facing international sanctions. But Guryev’s lawyers in London said the vessel isn’t his.

“As we have informed the Antiguan authorities Mr. Guryev neither owns nor controls the Alfa Nero and has simply used the vessel from time to time under commercial charter since 2014,” his legal representative wrote in reply to questions from Bloomberg.

Antigua Port Manager Darwin Telemaque on Tuesday said that if no one proves ownership of the Alfa Nero by March 31 he will be forced to put it up for auction. 

For “well over a year” the marina has been covering hefty fuel, electricity and food bills for the five-man crew, he said. The prime minister’s office considers the Alfa Nero an abandoned vessel and says it has run up a tab of more than $500,000. 

Read More: Antigua Plans to Sell Russian Tycoon’s ‘Abandoned’ Superyacht 

Now the concern is that the ship will become derelict and obstruct traffic in Antigua’s busiest harbor, Telemaque said.

“Our yachting industry is our largest maritime source of revenue, larger even than the cruise business,” he said in a telephone interview. “And we have to take every step we can to protect that and not allow the vessel to become a burden to our country.”

Guryev, who is worth of $10.1 billion according to the Bloomberg Billionaire’s Index, is the founder and largest shareholder of PhosAgro, one of Europe’s most dominant fertilizer companies.

He’s been sanctioned by the US, UK and the EU over his Kremlin ties amid the Russia-Ukraine war. Responding to a US request, Antiguan authorities last year searched the vessel, allowing the FBI to observe the operation.

Read More: Impounded Russian Superyachts Are Costing Millions to Maintain

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