Konstantin Rivkin said his client categorically denies the new charges.
The Prosecutor General's Office now claims that Khodorkovsky, the founder of the bankrupt Yukos oil company, and Lebedev are guilty of embezzling receipts from Yukos subsidiaries Fargoil and Ratibor, and of laundering the money through the Open Russia Foundation, a charitable organization established by Khodorkovsky in 2001 as a private endowment to assist academic institutions and non-governmental organizations in Russia.
Khodorkovsky and Lebedev, both serving eight-year sentences in Siberia since 2005 for fraud and tax evasion, were taken to a pre-trial detention facility in the regional center of Chita, in Eastern Siberia, in December 2006.
The former tycoon, who acquired his company during controversial privatization deals in the early-1990s, has insisted his case was orchestrated by the authorities to silence his criticism of President Vladimir Putin and as part of a campaign to bring mineral assets under Kremlin control.