MONACO (AFP).- The Russian billionaire owner of Monaco football club was in custody Tuesday, his lawyer confirmed, the latest twist in his legal battle with a Swiss art dealer who he claims cheated him of up to one billion dollars and Sotheby's auctioneers.

Police officers also carried out a search Tuesday morning of Dmitry Rybolovlev's luxury penthouse apartment in the principality, said a source close to the case.

Rybolovlev's lawyer Herve Temine confirmed the latest developments, while stressing the principle of the presumption of innocence.

Temine's colleague Thomas Giaccardi said the latest move came after the seizure and analysis of a mobile phone belonging to one of Rybolovlev's lawyers, Tetiana Bersheda.

Since 2015, Rybolovlev has been locked in a legal battle with Swiss art dealer Yves Bouvier, who he accuses of having swindled him out of up to a billion dollars, by charging inflated fees.

When Rybolovlev's lawyer Bersheda produced an audio recording from her mobile phone that she said supported his case, the investigating magistrate in the case ordered text messages from the same phone to be extracted.

That led to Monaco prosecutors opening a corruption investigation against Rybolovlev in 2017.

His legal team has repeatedly argued that this analysis of the phone was a violation of the lawyer-client confidentiality. That issue is still being fought out in court, but some of the compromising text messages have already been leaked to the French press.

On October 2 this year, Rybolovlev opened a new front in his legal battle, launching a $380-million (333-million-euros) lawsuit against Sotheby's auction house through the New York courts.

In it, he accused the auction house of having helped Bouvier, their art advisor, carry out "the largest art fraud in history" -- at his expense.

Rybolovlev says Bouvier tricked him over the acquisition of 38 works of art he bought from him over a decade for more than $2.1 billion.

"He repeatedly and blatantly misrepresented the acquisition prices for the paintings," pocketing the difference himself, says the lawsuit.

Sotheby's has dismissed the lawsuit as "entirely without merit".

In November 2017, it filed its own lawsuit against Rybolovlev in Switzerland and is seeking to have the action in New York dismissed.


© Agence France-Presse