Image for representational purpose only
Moscow: The health of Russian opposition figure Alexei Navalny, currently imprisoned in a penal camp, has significantly deteriorated, according to his chief of staff, Leonid Volkov.
"Since the end of last week he has been suffering from severe back pain," dpa news agency quoted Volkov as saying in a statement on Wednesday.
Navalny also had symptoms of paralysis in one leg and could no longer walk, he added.
Despite the pain, he had been given only two pills in total, said Volkov.
"Under all the circumstances known to us, the massive deterioration of his condition can only be cause for extreme concern," chief of staff said.
The staunch Kremlin critic was the "personal prisoner, the personal hostage of (Russian President) Vladimir Putin; a dangerous, crazy murderer", Volkov wrote on Twitter.
"Putin bears the personal responsibility for the life and the health of Alexei Navalny in the torture colony of Pokrow," he added.
The 44-year-old opposition figure was sentenced to imprisonment at the penal camp in Pokrow, about 100 km east of Moscow, in February for violating parole requirements from an earlier sentence, while he was recovering from a poisoning attack in Germany.
The dissident 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.
Volkov and Navalny's wife, Julia Navalnaya, also complained that the penal camp had not admitted Navalny's lawyers for a scheduled meeting with the opposition politician for the first time, citing other measures within the camp.
Volcov suspected that this was an attempt to cover up a possible admission of Navalny to the prison's hospital.
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.
Germany, the European Union and the US have repeatedly called for Navalny's release. 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.
(With inputs from agencies)