Moscow - Russian investigators on Tuesday charged popular protest leader Alexei Navalny with embezzlement in an old case that may put one of President Vladimir Putin's most vocal critics in jail for 10 years.
The Investigative Committee said in a statement that Navalny would also be barred from leaving Moscow during a probe into the opposition leader's time as an unofficial adviser to a small deal struck by a regional government in 2009.
The charismatic 36-year-old corporate lawyer by profession looked pale as he came out of closed hearings during which the charges against him were expanded substantially to include some of Russia's gravest business crimes.
"Something absolutely absurd and very strange has happened because they have completely changed the story behind the charge," the prominent anti-corruption blogger told reporters.
"I cannot imagine how the investigators can prove this. But probably they will prove it."
Navalny was already a cult figure with Russia's growing internet community for his campaign against state corruption when he helped spearhead the wave of protests that rocked the Kremlin in winter months.
Case dropped in the past
He has since emerged as one of the most prominent leaders of a splintered protest movement that has faced new challenges from authorities since Putin's disputed third presidential term began in May.
Several top protest organisers are being investigated on various charges. The newest ones against Navalny concerned a small business deal that was struck by a regional government he advised three years ago.
The case had been probed and dropped in the past. But Russia's powerful Investigative Committee chief Alexander Bastrykin personally demanded a review of the case earlier this month in comments broadcast on state TV news.
Investigators had originally accused Navalny of causing the regional budget a loss of $40 000 by advising a local state-owned timber firm to conclude a deal another small company in 2009-2010.
Navalny was not accused of profiting personally in the case but misleading the local governor whom he advised on an informal basis.
The charges released on Tuesday showed that the budget's loss had soared to $500 000.
Ordered to leave Moscow
Central Kirov region Governor Nikita Belykh has dismissed the case as a form of political pressure and stressed that local investigators had long concluded that Navalny had committed no crime.
The investigators on Tuesday pressed two counts against Navalny that include "misappropriation or embezzlement... committed by an organised group or on an especially large scale".
The offence carries a prison sentence of five to 10 years.
He was also charged with being an accomplice to a crime and ordered not to leave Moscow until the trial begin.
Navalny told reporters he could no longer rule out being arrested in the coming days or weeks.
"It is possible," he said. "If it is possible for them to say that I stole those 16 million [rubles] [$500 000], then anything is possible."
But he also vowed to continue his political activities despite the renewed pressure from the state.
"I will continue doing what I did before. Nothing has changed for me," said Navalny.