Lawyers for jailed Kremlin critic Alexei Navalny sounded the alarm Wednesday over the politician's deteriorating health in prison and demanded immediate access, saying he complained of back pain and leg numbness.
Last August President Vladimir Putin's most prominent critic survived a near-fatal poisoning with Novichok, a military-grade nerve agent, and was flown to Germany for treatment.
The 44-year-old was arrested upon his return to Russia in January and was sentenced to two-and-a-half-years in jail the following month. He is serving his sentence outside Moscow, in a penal colony notorious for harsh discipline.
Navalny's lawyer Olga Mikhailova said on Wednesday he had recently been complaining of strong back pain, adding that his leg has gone numb this week.
The opposition politician had seen a neurologist but the doctor had not said what was wrong with him, Mikhailova said, adding that Navalny had simply been given ibuprofen.
"That's all his treatment," she told AFP, adding that the painkiller did not help, while his leg went numb on Tuesday.
"I don't know what's wrong with him. He should be seen by a proper doctor," she said.
Mikhailova said she was not allowed to see Navalny on Wednesday.
Navalny's team expressed strong concern.
The opposition politician's right-hand man Leonid Volkov suggested the prison administration might be hiding the fact that he had been transferred to a prison infirmary.
"We don't know where Alexei Navalny is and why they are hiding him from his lawyers," Volkov said on Facebook.
- 'Life in danger' -
Maria Pevchikh, head of investigations at Navalny's Anti-Corruption Foundation, said: "The rapid deterioration of his health condition raises our extreme concerns."
"We believe that Navalny's life is in danger and demand immediate access to him for his lawyers," she tweeted.
Volkov said that on Thursday Navalny's lawyers would make a new attempt to see him in his prison in the town of Pokrov, located more than 100 kilometres (62 miles) east of Moscow.
Navalny himself has described the Pokrov prison as a "concentration camp", saying he was woken up every hour at night because he was considered a flight risk and guards recorded him on camera during his sleep.
Last month Navalny was sentenced to two and a half years in a penal colony for breaching parole terms while in Germany recovering from the poisoning attack.
On Tuesday, his team launched a campaign seeking Navalny's release and announced plans to stage what they said would be "modern Russia's biggest protest."
Navalny's allies urged supporters to register with the website free.navalny.com and mark their location on an online map.
The team said they would set a date for the protest once 500,000 supporters have been registered.
As of Wednesday, 200,000 people have signed up, including more than 40,000 people in Moscow and over 22,000 in the second city Saint Petersburg.
Tens of thousands of Navalny supporters took to the streets across Russia in January and February but those rallies were broken up and more than 10,000 were detained.
Washington and Brussels have demanded Navalny's immediate release and imposed sanctions on Russian officials over his poisoning. On Wednesday, Canada followed suit, slapping sanctions against nine Russian officials in response to "gross" rights violations and Navalny's silencing.