At the time of his sentencing in April last year, his supporters argued that imprisonment could cost him his life, with the politician already suffering from a serious nerve condition after twice being mysteriously poisoned.
Since the sudden death of opposition leader Alexei Navalny in February, those fears have intensified.
“Given the Russian authorities’ track record of obfuscation and false statements, his actual location cannot be ascertained,” the Free Russia Foundation, an NGO, said in a statement, calling the refusal to allow his lawyers to visit a breach of Russian and international norms.
Kara-Murza, a dual Russian-British citizen, is rumored to be among those slated for a possible prisoner swap, alongside jailed U.S. reporter Evan Gershkovich and former U.S. marine, Paul Whelan.
