Russian billionaire Mikhail Prokhorov is seeking buyers for all of his assets just three months after his business offices were raided by the Federal Security Service (FSB).

The party-loving bachelor, dubbed the "Great Gatsby oligarch" in a bne IntelliNews profile in June, has fallen foul of the Kremlin following a series of investigative reports by his RBC media holding into individuals close to the Kremlin.  

A source close to Prokhorov's Onexim investment group told bne IntelliNews that the group believes the raids were authorised by President Vladimir Putin himself after RBC reported on the business dealings of his daughter Ekaterina and her husband Kirill Shamalov. "You can imagine the reporting on such a sensitive issue for the president must have gone down like a lead balloon in the Kremlin," says the source. "It stirred the hornet’s nest."

Prokhorov, whose fortune of $15bn more than halved since 2011, has already put his 20% stake in potash producer Uralkali, his power utility Quadra, as well as RBC up for sale. Now, the Vedomosti financial daily reports that the 51-year-old businessman has decided to organise a fire sale of all of his assets, including stakes in miner Rusal, investment bank Renaissance Capital, consumer lender Renaissance Credit, real estate holding OPIN and the high-brow online magazine Snob.

Negotiations over the sale of OPIN to Moscow Credit Bank's owner Roman Avdeev are already underway, according to Vedomosti.

Dmitry Razumov, chief executive of Onexim, issued a statement after the Vedomosti report, saying it wasn't accurate to say the group was "selling all of our Russian assets."

"No such decision has bee made," the statement said. "Onexim Group, was, is and will remain a major player in the Russia market, maintaining a strategic interest in investments here in Russia. First and foremost among these involves the financial sector, where we plan to devote particular attention to our banking institutions Renaissance Credit, Renaissance Capital, IFC Bank and the Soglassye insurance company.

Like the F. Scott Fitzgerald literary creation, Prokhorov is somewhat of a dilettante; his interest in politics, media and electrical cars all seem to have been passing fads. His love of basketball may be genuine, but his acquisition of an American NBA team seems to have been more about making a buck from real estate and rubbing shoulders with New York's gilded gliteratti, such as rapper Jay-Z and former mayor Michael Bloomberg. Prokhorov's team, the Brooklyn Nets, have gone from "contender to laughing stock", according to a June 2 analysis by isportsweb.

Media track into trouble

But it is his dabbling in media that has put him firmly in the Kremlin's doghouse. On April 14, Masked officials from the FSB and tax inspectors swooped on the offices of Onexim and several of its subsidiary companies, including investment bank RenCap.

RBC, which used to have reputation for running paid reporting, had been transformed in the past two years into an independent media organisation with a penchant for hard-hitting investigations into high-level corruption. The media group, which claims to have a combined monthly audience of 22mn across its newspaper, website and TV channel, for example went big on the Panama Papers, which showed Putin's cello-playing childhood pal, Sergei Roldugin, had stashed significant wealth offshore. It also ran a story about an oyster farm that it claimed had opened conveniently near a huge stately pile – known as "Putin’s Palace" – on the Black Sea.

In an apparent attempt at damage limitation, Prokhorov has dismissed the senior editorial team at RBC, but there is still speculation that the media group will now have to be sold at a massive loss to a Kremlin-friendly holding.

The Russian press have suggested that RBC's aggressive coverage of Putin stemmed from Prokhorov's anger at the Kremlin-controlled lenders for refusing to agree on bailout terms for Quadra, his utility formerly known as TGK-4. Prokhorov is said to be irked by rival tycoons receiving more favourable terms and had hoped to use the media spotlight as leverage.

The raids on Prokhorov's businesses also triggered a run on his MFK bank. Wealthy individuals withdrew almost RUB10bn ($156mn) from the lender in the same month as the FSB inspections.

Prokhorov once said he completely overhauls the scope of his business activities every eight years. Exactly eight years ago, his life took a big change when he split with former business partner Vladimir Potanin and became interested in politics and the media. Putin is understood to have helped broker the bitter divorce settlement with Potanin.

In 2011, he caused a sensation by becoming leader of the pro-Kremlin Right Cause party and inviting Alla Pugacheva, a Russian singer with the fame and baggage of Madonna, to join his camp.

His rapid rise in politics and decision to stand in the 2012 presidential elections was widely perceived as part of a Kremlin ploy to have a loyal party secure the liberal vote and soak up some of the public dissension stemming from the rigged parliamentary elections and the subsequent protests. Prokhorov finished third with less than 8% of the vote and later withdrew from politics, calling his own party "senseless".

Raids on oligarchs are nothing new on Putin's watch. Media mogul Vladimir Gusinsky had his offices raided in 2000 as part of fraud investigation before he fled to exile in Israel. In 2004, tax officials raided the offices of oil firm Yukos in a politically-contrived case against its owner Mikhail Khodorkovsky, a Putin critic who was later jailed. In 2014, billionaire Vladimir Evtushenkov spent several months under house arrest on suspicion of money laundering before being released and seeing his Bashneft oil asset nationalised.

Sources close to Prokhorov's companies said they hoped the raids are just a shot across the bows and not a red card. "The raids on his businesses were meant to stir him into action over RBC, which has happened, and I don't expect any further repercussions," Tom Adshead, chief operating officer at Macro Advisory, told bne IntelliNews. "No doubt he has his enemies, but he's been a loyal participant in the Russian political process, and has a role to play, so I don't think he'll be persecuted over a relatively minor issue."