The media is reporting Lebedev has been in solitary confinement since 19 August as punishment for refusing to participate in daily walks outside his cell and for "insulting" guards.
The statement says "Platon is seriously ill and has simply not been in a condition for more than a year to go out for his prison walks."
Khodorkovskii and Lebedev were sentenced on 31 May to nine years imprisonment following conviction on charges of massive fraud, tax evasion, and embezzlement.
Their supporters say they are victims of a Kremlin-inspired campaign to punish Khordorkovskii for his political ambitions. The Kremlin has denied any involvement in the case.
Khodorkovskii Sentenced To Nine Years In Prison
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