He is Russia's third richest man and has been described as its most eligible bachelor. He owns a top U.S. basketball team.
Now, Mikhail Prokhorov is vying for his country's top office, reinventing himself as a politician with an "obsession" about Russia's future and a plan to put it on the right track.
In a career turn that would have seemed unthinkable for any of Russia's billionaire tycoons just a year or so ago, Mr. Prokhorov is seeking to run against Prime Minister Vladimir Putin – in power for the past 12 years – in a March 4 presidential vote.
Mr. Putin is expected to win despite declining popularity and big December street protests that exposed dissatisfaction among many Russians with his plan to return to the Kremlin. Mr. Prokhorov said he hopes to beat Mr. Putin, but made clear he views the vote as a springboard to a lasting political role.
"Maybe it sounds a little bit corny, but I love my country," Mr. Prokhorov, who spent part of a fortune rooted in the 1990s privatization of a huge Arctic mining operation to buy the New Jersey Nets basketball team, said in an interview.
"And really, I see a lot of problems – and I know the answers."
His chances of success above all with liberal, middle-class voters he targets may be clouded by resentment of Russia's "oligarchs" and suspicions that his candidacy is a "Kremlin project" meant to blunt opposition to Mr. Putin rather than increasing pressure on him.
There was no portrait of Mr. Putin or President Dmitry Medvedev in his office, where he sat for the interview beneath a windowed dome.
The trophies and artifacts there included a Lladro porcelain basketball player making a shot, a gold-coloured sneaker from "sports veterans" of Norilsk Nickel – the metals miner he sold his stake in before the 2008 financial crisis – and pieces ranging from a silver bull, as in bull market, to a mammoth and a Matryoshka doll.
Unmounted and obscured by a partition behind his big desk, however, a picture of Mr. Prokhorov with former finance minister Alexei Kudrin provided a hint of Mr. Prokhorov's liberal political agenda. Mr. Kudrin was forced out in September and is urging Mr. Putin to loosen his grip and enact democratic reforms.
In an interview with Reuters, he invoked Abraham Lincoln. His 6-foot-8, somewhat gaunt frame and narrow face hint at a physical resemblance. "Government should be of the people, by the people and for the people – and we have had government at the expense of the people."
Mr. Putin, he said, had been "very efficient" for the first five or six years of his 2000-2008 presidency, but "we need to change the strategy – from stability to very active movement." Russia was "lagging behind compared to the rest of the world."
"We are ready to fight for the future of Russia being one of the most transparent, open, democratic countries of the world," said Mr. Prokhorov, 46, who wore an unassuming dark suit, blue shirt and patterned necktie. "This is my obsession."
The biggest opposition protests of Mr. Putin's rule were fuelled by suspicions that his United Russia party benefited from widespread electoral fraud even though its parliamentary majority was sharply cut in a Dec. 4 election.
Both the vote result and the protests have shaken Mr. Putin's grip as he seeks at least six more years in power, showing many Russians are tired of a tightly controlled political system in which they feel they have no voice.
Mr. Prokhorov was a stranger to politics until last year, when he briefly headed a Kremlin-backed liberal party but quit in a dispute with Vladislav Surkov, the influential strategist behind Mr. Putin's consolidation of power.
But Mr. Prokhorov is widely seen as less of a challenge than a crutch for Mr. Putin; a safe candidate who could lend legitimacy to the presidential election and split the opposition.
Mr. Prokhorov poses no threat to Mr. Putin because he is "practically a caricature of an oligarch whom millions of voters by definition will never support," said Nikolai Petrov, a political analyst at the Carnegie Moscow Center.
Mr. Prokhorov, who owns aluminum, gold and banking assets, is ranked by Forbes magazine as Russia's third-richest man and No. 32 in the world, with an $18-billion fortune.
A rare Russian bachelor at his age, Mr. Prokhorov has a reputation for late nights out and luxury ski vacations.
He caused a stir at home and abroad in 2007 when French police detained him on suspicion of arranging prostitutes for guests at a Courchevel, France, ski resort.
He denied any wrongdoing and was later cleared, but analysts say the incident undermines his political viability and could allow the Kremlin to keep him on a short leash.
"Prokhorov has been embroiled in too many scandals to count on becoming a popular politician," Mr. Petrov said. "He can always be held back."
Mr. Prokhorov disputed that view, contending that the playboy image was an attraction for some Russians – and even calling the Courchevel incident "the beginning of my political career."
"A miracle happened. Because before the Courchevel case, nobody in Russia knew me," he said. "After this I became more or less popular."
Business and politics have proved a dangerous mix under Mr. Putin, who reined in Russia's tycoons during his first term as president.
Oil magnate Mikhail Khodorkovsky was arrested in 2003 and is due to stay in prison until late 2016 after two trials Kremlin critics say were part of a campaign to seize his assets and punish him for challenging Mr. Putin by funding the opposition.
Mr. Prokhorov said Mr. Khodorkovsky's fate "was a very bad precedent," allowing officials at all levels to persecute businessmen for power and profit, and said he would free him immediately if elected.