Is Vladimir Putin the richest man on earth? Russian President Vladimir Putin at a meeting in Russia. Picture: AP Photo/Ria Novosti Source: AP MOVE over Bill Gates there's a new rich kid on the block. Vladimir Putin could be the world's richest man if estimates of his wealth prove correct. The thing is, when you're dealing with the ex-KGB President of a notoriously secretive nation with a seat on the UN Security Council and nuclear weapons at his disposal, it's really hard to know. Theories about Putin's wealth are wrapped up in leaked diplomatic cables and shell companies. Most reports around the issue site a 2007 interview that German newspaper Die Welt conducted with a member of the Moscow high society, Stanislav Belkovsky. In the interview, Belkovsky claimed Putin controlled 37 per cent of oil company Surgutneftegaz and 4.5 per cent of natural gas monopoly Gazprom, giving him a fortune of about US$40 billion - the market price of these stakes at the time, Bloomberg reports. Vladimir Putin off for a horse ride. Belkovsky has since said Putin's stake could now be worth between $60-70 billion, putting him in contention with Bill Gates, the wealthiest man in the world with a $72 billion fortune. However there is no evidence Putin actually does own a stake in the companies. The Russian leader denied it when asked in 2008, telling reporters it was just "chitchat, nonsense, nothing to discuss," according to Bloomberg. "They picked it out of their noses and smeared it on their pieces of paper," he said. However others just can't get their head around the fact the Russian President has a collection of luxury watches, yachts and palatial homes, despite declaring an income of less than $200,000 a year and a few paltry properties as assets, the Bureau of Investigative Journalism reports. Russian opposition leader Boris Nemtsov has also written a book on the subject, saying Putin has about 20 homes, four yachts and 58 aircraft, meaning the money must be coming from somewhere. But seeing as he's got the KGB and some of the world's largest oil and gas reserves at it disposal, who's really going to argue? We wouldn't want to pick a fight. Just another day, being Putin. Putin goes diving. Putin the horse whisperer. Putin does diplomacy Picture: AP. Do you think Putin is secretly rich?