Russian President Vladimir Putin once said that as a poorly paid politician, he worked "like a galley slave." He refers to himself in public as "your humble servant" and he reported his official income last year was $187,000.
His official list of assets include a small apartment and three cheap cars. Clearly, Putin has more. But how much more?
Speculation about Putin's net worth has long been one of the biggest parlor games in wealth and political circles. And now with Putin taking center stage in the crisis over Syria, his power and wealth have once again come under the spotlight.
(Read more: More 'innocent victims' if US strikes Syria: Putin )
Wealth in Russia is often held through shell companies, offshore accounts and frontmen. So despite efforts by many reporters over the years, no one has been able to pin a precise dollar number on Putin's fortune.
Putin and his representatives have long denied rumors of his wealth, saying they are baseless. But Russian political insiders and opponents of Putin have claimed his wealth could be in the billions.
In a memo disclosed by WikiLeaks, former Secretary of State Condoleezza Rice quotes a Russian opposition figure as saying that "Vladimir Putin is nervously trying to secure his future immunity from potential law enforcement investigations into his alleged illicit proceeds."
In interviews with The Guardian, Die Welt and other overseas media, Russian political analyst Stanislav Belkovsky estimated Putin's wealth at more than $40 billion. He said Putin has shares in three oil and gas companies, including Surgutneftegas and Gazprom, through offshore trusts.
In a leaked cable from 2008, former U.S. Ambassador to Russia John Beyrle repeated rumors that Putin was linked with Swiss trading firm Gunvor.
"The company is rumored to be one of Putin's sources of undisclosed wealth," Beyrle wrote, attributing the information to oil traders. Putin and Gunvor denied the claim.
Putin's presidential perks are also substantial. In a 32-page report, with the sardonic title "The Life of a Galley Slave," former political leader and Putin critic Boris Nemtsov details the fleet of cars, planes and boats at the president's disposal.
(Read more: Homes of governors)
It said Putin has 20 homes, four yachts and a wealth of other presidential assets. It said he has 58 aircraft, including 15 helicopters and 43 other aircraft, including an Airbus, two Dassault Falcon jets and an Ilyushin airliner with an $18 million cabin outfitted by a jeweler.
The report also said that Putin's four yachts include a 176-foot vessel with a spa pool and waterfall and a more elaborate five-deck boat with a barbecue.
—By CNBC's Robert Frank. Follow him on Twitter @robtfrank.