Russia's leading corruption whistleblower on Friday accused Prime Minister Vladimir Putin's close ally Igor Shuvalov of graft.
Alexei Navalny posted on his blog the scans of documents that show tens of millions of U.S. dollars transferred to the account of Shuvalov's company from companies that Navalny alleges are owned by billionaires Roman Abramovich and Alisher Usmanov.
Navalny's disclosure follows articles in the Financial Times and the Wall Street Journal earlier this week that mentioned the same murky deals.
Since 2008, Shuvalov, a deputy prime minister, has overseen investment, economics and finance in Putin's government. Shuvalov said his family's income was 1.4 billion rubles ($48 million) between 2008 and 2001, most of which came from his wife. They also declared ownership of upmarket properties in Russia and overseas.
Shuvalov insisted that he accumulated wealth before he became a public servant in 1997, and that he paid all the necessary taxes. He has denied any wrongdoing.
The Shuvalovs made hefty returns on investments in shares of the gas monopolist Gazprom by buying them before a market liberalization law was enacted to boost the shares' value. Shuvalov's allies deny the deputy prime minister had any insider knowledge.
In a rare public statement Alexander Voloshin, former presidential chief of staff, wrote on his blog on the Ekho Moskvy website on Thursday that the liberalization of the Russian gas market was a common knowledge before it happened and that "at the time of buying the shares Igor did not have any sacred knowledge different from what everybody already knew."
Voloshin also suggested that the "PR campaign" against Shuvalov, known for his liberal views, could have been orchestrated by his "foes and ill-wishers" who oppose a further liberalization of the economy and don't want to see him in the next government.
Prompted by Navalny, the hashtag "ShuvalovThief" in Russian was briefly trending on Twitter.