The imprisoned former chief of the Russian oil firm Yukos has rejected new charges brought against him, saying he has no doubt that politicized Russian courts will find him guilty.

Mikhail Khodorkovsky, in a statement, called the court proceedings an effort to steal the Yukos oil company. He said those who devised the cases are afraid to see him free and want to make sure he stays in prison.

Khodorkovsky and his business partner Platon Lebedev are serving eight-year terms in a Siberian prison camp following conviction on fraud and tax evasion charges. They would have been eligible for parole this year, but the new money laundering charges filed against them Monday will probably eliminate any chance for early release.

Khodorkovsky's supporters have called the charges against him reprisals for his support of opposition politicians. Kremlin authorities deny this.

Meanwhile, Khodorkovsky's lawyer says Russian authorities briefly detained her as she sought to fly home to Moscow from Chita. She says they forced her to sign a statement promising not to reveal details of the new case against the former oil tycoon.

Some information for this report was provided by AFP and AP.