Fears are growing for Vladimir Putin's main opposition leader Alexei Navalny after he was shown looking gaunt and frail after solitary confinement.
Navalny was put inside a dungeon-like space in Penal Colony 6 in Melekhovo.
He has earned the wrath of Putin for standing up to him and gaining supporters, appealing for a democratic Russia instead of the one currently blighted by Putin's oppression.
The "torture prison" described by Navalny as a "concrete kennel" is causing concern for his health after the first photograph of him since June was seen.
"I’ve just hit the jackpot. As soon as I got out… they sent me back there for another 15 days,” said Navalny, 46, on his Twitter account run by his associates.
"By the way, you gotta admire the pettiness of these crooks.
"My wife and parents had been waiting for a visit to me for four months, and now it's coming up, and they're moving me to strict conditions."
Once poisoned by Novichok, a toxic substance considered the signature method of assassination by the Russian security services, Navalny is behind bars on trumped up corruption charges.
He has now spent over 600 days in prison since and it is believed his most recent harsh punishment may have been due to calling for Russians to vote against Putin in local elections.
In 2021, Navalny ended a 24-day hunger strike and complained of numbness and back pain.
His chief of staff, Leonid Volkov, said: "Suddenly, three weeks ago, they started to dramatically worsen his conditions, which actually poses an enormous threat to his health, because no normal person could spend a long time in that 'special' cell.
"And for Alexei, who had just survived the poisoning, it is especially dangerous.”
He also warned: "The fact that Putin is losing (the war), and is getting less and less predictable, makes the situation more dangerous.”
The opposition leader called on Russians to use their votes in municipal and regional election votes on Sunday, Navalny said on Telegram.
"Any action aimed at weakening any of the elements of the Putinist system is right and it is the duty of every citizen."
He said Putin "continues to rule with repression, control over the judiciary system, propaganda and his party, United Russia, which controls all the deputy assemblies in the country".
"By participating in the Smart Vote, you will vote against war, lies, corruption and misery."
The jailed lawyer also wished a happy 21st birthday to his daughter Dasha.
He said: "21 years old. This is simply unbelievable. Happy birthday, Dasha. Mum and myself are very happy to have you.
"Life is wonderful, walk it bravely. Miss you terribly. Love you so much."
