Veteran Russian tycoon and senator of the Republic of Dagestan Suleyman Kerimov was detained by police in the French Riviera on November 20, Tass reported, citing a representative of French embassy in Russia. Reportedly Kerimov was detained in Nice on tax evasion charges, according to the BBC. 

Previously local press reported that Kerimov is the actual owner of the Hier villa on the Antibes acquired by Swiss real estate family heir Alexander Studhalter for €35mn, while the actual cost of the villa is estimated at €150mn.

"Currently Russian foreign representatives in France are in constant contact with authorities to achieve the immediate release of Kerimov," the press service of the Russian embassy told Interfax.

The Russian Foreign Affairs Ministry noted that Kerimov is using a diplomatic passport and cannot be detained in the territory of a foreign state.

Vedomosti daily said that since 2013 Kerimov had to comply with Russian legislation and transfer his assets to a blind Swiss trust, the Suleyman Kerimov Foundation, including a stake in Russia's largest gold miner Polyus Gold.

Some of the assets later migrated to Wandle Holdings Limited and Sacturino Ltd, controlled by Kerimov's son Said Kerimov. As of 2016 Forbes estimated Suleyman Kerimov's wealth at $6.3bn, making him Russia's 21st richest man.

Legal experts surveyed by Vedomosti noted that if tax evasion exceeds 5% of the total income tax paid, the case becomes criminal,  with a threat of imprisonment of one to five years and a fine of up to €250,000.