Russian tycoon Dimitri Rybolovlev, the owner of Monaco’s football club, has been detained in the principality in an investigation into suspected corruption and other allegations.
Lawyer Frank Michel said Mr Rybolovlev was detained on Tuesday in Monaco.
The newspaper Le Monde, which first reported the detention, said the tycoon’s home was searched.
Mr Michel is the Monaco lawyer for Swiss art dealer, Yves Bouvier, who has lodged a legal complaint for corruption and money laundering that centres on a lawyer for Mr Rybolovlev.
They acknowledged on Tuesday that he was being questioned.
The Russian Embassy in Paris, which oversees Monaco, said it is aware of the detention and asked Monaco authorities for information but has not received a response.