Citing sources inside the president's administration, Russian political expert Stanislav Belkovsky claims that after eight years in power Putin has secretly accumulated more than $40 billion (£20bn). The sum would make him Russia's - and Europe's - richest man.
In an interview with the Guardian , Belkovsky repeated his claims that Putin owns vast holdings in three Russian oil and gas companies, concealed behind a "non-transparent network of offshore trusts".
Putin "effectively" controls 37% of the shares of Surgutneftegaz, an oil exploration company and Russia's third biggest oil producer, worth $20bn, he says. He also owns 4.5% of Gazprom, and "at least 75%" of Gunvor, a mysterious Swiss-based oil trader, founded by Gennady Timchenko, a friend of the president's .
"Putin's name doesn't appear on any shareholders' register, of course. There is a non-transparent scheme of successive ownership of offshore companies and funds. The final point is in Zug in Switzerland and Liechtenstein. Vladimir Putin should be the beneficiary owner."
Belkovsky adds that the west has misunderstood Putin and has been distracted by his "neo-Soviet" image. Putin, Belkovsky claims, is ultimately a "classic" businessman who believes money can solve any problem .
The wave of renationalisations under Putin has transformed Putin's associates into multimillionaires. Members of Putin's cabinet personally control the most important sectors of the economy - oil, gas and defence. Medvedev is chairman of Gazprom; Sechin runs Rosneft; other ministers are chairmen of Russian railways, Aeroflot, a nuclear fuel giant and an energy transport enterprise . Putin has created a new, more streamlined oligarchy, his critics say.
"The crown jewels of the country's wealth have ended up in the hands of Putin's inner circle," Vladimir Rzyhkov - a former independent MP .
Putin has not commented on Belkovsky's claims . Putin's chief spokesman, Dmitry Peskov, was not available for comment . Gunvor, which has its head office in Geneva, failed to comment