A Siberian court rejected a request for parole on August 22 from Khodorkovsky, 45, who is serving an eight-year prison term for fraud and tax evasion.
The court ruling has been appealed against in a higher court, Semyon Rozenberg said. "The documents have been sent to the district court, but have not been received yet."
Khodorkovsky, the founder of what was once the country's largest oil company, was arrested in October 2003 and convicted in May 2005. Earlier this year new charges were filed against him, of laundering billions of dollars and stealing huge volumes of oil.
The Yukos oil company formally ceased to exist in November 2007, after the company's assets were sold off through a series of liquidation auctions to meet vast creditor claims. State oil company Rosneft bought up the lion's share of the production assets, becoming Russia's largest oil producer.
Khodorkovsky, an outspoken critic of former president Vladimir Putin, has consistently denied all charges against him, saying he was punished for supporting the opposition, and that the liquidation of Yukos was engineered by corrupt government officials aiming to seize lucrative oil assets.
His parole request, filed on July 16, came after the election of President Dmitry Medvedev in March. The new pro-business leader had suggested that Khodorkovsky could eventually be pardoned, and has pledged major reforms to Russia's judiciary, aimed at creating an independent court system free of bribery and corruption.
Khodorkovsky's chances of parole have been severely damaged by the latest charges, brought by prosecutors in June against him and his business partner Platon Lebedev, also serving an eight-year jail term for fraud and tax evasion, of laundering $28.3 billion and stealing oil between 1998 and 2004.
Khodorkovsky told Russian business daily Vedomosti in an interview published last month that he has no intention of returning to the Russian oil industry and will not contest the rulings against Yukos.