The Moscow City Court has rejected an appeal by former Yukos oil executive Mikhail Khodorkovsky to be freed on bail until his trial.
The ruling means Mr. Khodorkovsky will remain behind bars at Moscow's Tishina prison until March 25, awaiting trial on multiple charges of tax evasion and fraud.
The judge let stand an earlier court ruling that extended Mr. Khodorkovsky's pre-trial detention by three months.
The hearing was open to media coverage, although no television cameras were allowed inside.
Appearing via video-link from prison, Mr. Khodorkovsky asked the court to change the terms of his incarceration to house arrest. He said he believed it was illegal for him to be held in custody and assured the court that he would not flee if released.
Mr. Khodorkovsky was arrested last October by members of Russia's Federal Security Service, the successor agency to the KGB.
The move was widely criticized in the West and even by some in Russia who viewed it as retaliation for Mr. Khodorkovsky's financing of opposition political parties running against Russian President Vladimir Putin's allies in last month's parliamentary elections.
The appeal ruling came as little surprise, especially to Mr. Khodorkovsky's lawyer, Genrikh Padva.
Mr. Padva said he and Mr. Khodorkovsky knew what they were up against going in. But he said they believe fully in their position and will be considering whether to file another appeal.
But few people expect Mr. Khodorkovsky to be released from jail before Russia's March 14 presidential poll, which President Putin is expected to win easily. Mr. Khodorkovsky faces many years in jail if he is convicted.