Khodorkovsky, 45, is facing an extension to his eight-year sentence on new embezzlement and money laundering charges totaling about $50 billion. His defense team has dismissed them as totally unsubstantiated.
"He is unrivaled in his knowledge of corporate law and the oil industry," Marina Khodorkovskaya said live on Ekho Moskvy, adding her son planned to prove the absurdity of the charges.
Khodorkovsky and his business partner, Platon Lebedev, are accused among other things of misappropriating and legalizing stakes in Yukos's affiliate, Eastern Oil Company (VNK), in 1998-2000.
The businessmen are now in a Moscow detention center after their transfer from a Siberian prison, where they have been serving sentences on fraud and tax evasion charges, which critics say were orchestrated by the Kremlin, since 2006.
Hearings on the new charges are due to begin on March 31. The defense said a fair verdict was unlikely and vowed to appeal to the European Court of Human Rights if their clients were convicted again.
A Moscow court rejected during preliminary hearings earlier this month the defense lawyers' request to drop the new charges and their request to return the case for further investigation. Their demands to dismiss the presiding judge and prosecutors in the case were also turned down.