Detectives had carried out an investigation suggesting that prostitutes had been procured for guests.
Those held for questioning included several Russian businessmen and eight women in their twenties who said they were models accompanying Mr Prokhorov.
Sources close to Abramovich have also denied he was behind the purchase of Villa Leopolda but both French and Russian media insist the transaction involved a Russian billionaire.
But Prokhorov's spokesman said the magnate was not behind the deal and said his boss would not do business in France until authorities apologise for briefly detaining him in a prostitution probe last year in the sky resort of Courchevel."Before the conflict with French authorities is settled and before he gets an apology from the French side, neither Onexim nor Prokhorov himself would do any business in France," said Sergei Chernitsyn, referring to the metal tycoon's investment vehicle, Onexim Holdings.
In January 2007 it was believed that Muscovite call girls were being flown to Courchevel to "entertain" the hundreds of super-rich businessman who stay at the resort each January for the Russian New Year.
Those whispers grew louder earlier this year, when reports suggested concrete interest in United from Beijing, while the Magpies are now sponsored by far Eastern gaming company Fun888.
But Ashley may have to wait on a Chinese bid for Newcastle, at least while challenges in China to a recently passed law restricting domestic businesses there from investing abroad are debated.