Jailed Kremlin criticis in great pain, his lawyer said Thursday after visiting him in prison, adding that allies were afraid for his life.
"He is suffering from strong back pain and pain in his right leg," lawyer Olga Mikhailova said in remarks on Dozhd television. "Everyone is afraid for his life and health."
Earlier this month,to a prison facility about 90 miles outside of Moscow and placed into an isolation cell, his lawyer Vadim Kobzev told CBS News.
Navalny was arrested on January 17 immediately upon his return to Moscow from Germany, where he spent five months recovering from poisoning with a Soviet-era nerve agent. His arrest prompted weeks of mass protests, with thousands rallying on the streets of Russian cities, including the capital, where large crowds gathered at outside the detention facility where he had been held until last week.
Thousands of people were detained amid fierce clashes with riot police.
Navalny was sentenced to two and a half years in prison last month for violating the terms of a previous suspended sentence. He has always dismissed all the charges against him as politically motivated.
Earlier this month, the Biden administration announced it wason seven senior Russian government officials in response to Navalny's poisoning and detention.
Alexandra Odynova contributed to this report.