CNN  — 

Russian authorities have ratcheted up pressure on opposition politician Alexey Navalny, leveling a new fraud accusation and jail threat against him in recent days.

Russia’s main investigative body said on Tuesday that it had launched a new criminal case against Navalny on charges of fraud related to his alleged mishandling of $5 million in donations to his Anti-Corruption Foundation and other organizations.

The foundation has been the subject of a number of criminal and administrative cases, which Navalny and his allies believe are politically motivated.

“It was found that for the needs of a number of non-profit organizations, including the Anti-Corruption Foundation … more than 588 million rubles [$7.9 million] have been collected from individuals as donations,” the Investigative Committee said in a statement. “These funds were intended solely for the purposes of these foundations.”

The Investigative Committee alleges that Navalny, as the head of these organizations, conspired with others and “spent more than 356 million rubles [$4.8 million] of these funds on personal [expenses],” including purchases of property and “holidays abroad.”

“Thus, the funds collected from citizens have been stolen,” the committee said.

The move came after Russian penal authorities threatened to jail the opposition politician for failing to comply with the terms of his suspended sentence in a yearsold case if he failed to show up for a hearing in Moscow on Tuesday morning – an implausible timeline given the 10 hours’ notice.

Navalny, who is currently in Germany after receiving treatment at Berlin’s Charite clinic following his poisoning in August with the nerve agent Novichok that he blamed on the Kremlin, mocked the probe on Tuesday.

“It looks like Putin is in hysterics,” Navalny said of the Russian President on Twitter.

A recent investigation by CNN in cooperation with the investigative journalism website Bellingcat revealed that an FSB toxins team of about six to 10 agents trailed Navalny for more than three years before he was poisoned in August with the lethal nerve agent.

That report was followed by the revelation by a Russian agent sent to tail Navalny that they planted the nerve agent in his underpants, a detail that emerged when Navalny called the man and, posing as a member of Russia’s National Security Council, pressed him for details of the operation.

Navalny said the cases by the Russian authorities were an attempt to put him behind bars, or block him from returning to the country.

“This was not that hard to predict. I said from the beginning … they will try to jail me because I didn’t die on the plane and then tracked down my assassins. Because I proved that Putin is behind it and that he is a thief who is ready to kill those who refused to be silent about his thievery,” Navalny said in a post on Instagram on Tuesday.

“I haven’t been silent even before an attempt on my life, now even more so I won’t remain silent.”

Navalny has repeatedly accused Putin of ordering his poisoning. The Kremlin has denied the claim.