Amnesty had stripped Navalny of the designation in February, arguing his past comments qualified as advocacy of hatred.
Russia has launched three new criminal investigations against Alexey Navalny, the jailed Kremlin critic claims, a move his allies fear could keep him behind bars for many more years.
In an Instagram post on Tuesday, Navalny said he had learned about the cases from an investigator who visited him in custody a day earlier.
The 44-year-old is currently imprisoned in a penal colony east of Moscow, serving a two-and-a-half-year jail sentence for alleged parole violations relating to a 2014 embezzlement conviction he dismisses as fabricated.
He was arrested in January upon his return to Russia from Germany, where he spent five months recovering from a nerve agent poisoning that he blames on the Kremlin.
“I’m becoming a more hardened criminal every day,” Navalny joked in the Instagram post. “So don’t think I’m only sitting in a cell, drinking tea and doing nothing.”
He said investigators were looking into his alleged mishandling of nearly $5m of donations given to his Anti-Corruption Foundation (FBK), and had accused him of insulting judge Vera Akimova.
Akimova presided over a defamation case in February against Navalny that saw him convicted of insulting a World War II veteran. He has also rejected that case as baseless.
Navalny said he had also been accused of creating a non-commercial organisation and encouraging Russians to abandon “their civic duties” by publishing an investigation into President Vladimir Putin’s allegedly vast personal wealth.
Navalny in January released a probe into a Black Sea palace Russian tycoons allegedly built for Putin.
The video has racked up more than 116 million views on YouTube. Putin denies the palace is his.
Citing investigators, the Kremlin critic said the three new probes were all of “high priority” and had more than 20 investigators working on them.
Navalny’s allies feared the fresh claims against him could extend his time in prison.
“Putin has decided to keep Navalny in prison for life,” aide Maria Pevchikh tweeted. “It’s more convenient for him that way.”
The new charges were announced as pressure builds on Russia’s political opposition ahead of September’s parliamentary elections.
Next month, a court hearing will take place to determine whether Navalny’s network of regional offices and his FBK should be categorised as “extremist” by Russian authorities.
In a bid to shield its members and supporters from possible prosecution, Navalny’s network disbanded before the ruling.
Most of his top allies have since been placed under house arrest or left Russia.
Russia’s financial monitoring service Rosfinmonitoring has already added Navalny’s political network to its database of “terrorist and extremist” organisations.
In an apparent further blow to Navalny’s circle, Russian politicians recently signalled their approval for legislation that would ban members of “extremist” organisations from becoming legislators.
Navalny’s imprisonment this year led to nationwide anti-government protests.
The Kremlin denounced the rallies as illegal as authorities arrested thousands who attended.