Former Yukos oil boss Mikhail Khodorkovsky and his business partner Platon Lebedev left their Moscow detention center on Friday to be transferred to a prison to serve the rest of their sentences for tax evasion and embezzlement, their lawyers said.
The families and lawyers of the two men say they do not know where they are being sent.
Khodorkovsky could be sent to any of Russia's 753 penitentiaries, his lawyer Natalya Terekhova said.
Under Russian law, convicts are sent to prison less than 10 days after the pretrial detention center is notified that court's sentence has taken effect. Lawyers for Khodorkovsky and Lebedev said previously that it is very possible they would be sent back to the same prison camps where they served their first jail terms.
After the convict's arrival at a prison camp, the Federal Penitentiary Service has 10 days to notify one of the convict's relatives of the exact address of the facility.
Lawyers for the pair, who have been named "prisoners of conscience" by Amnesty International, said they and family members were denied access to the pair on Friday.
"Khodorkovsky's wife has just been refused access to him for a meeting in the isolation cell, and was told that at 12:00 today he will be sent to a prison camp," Terekhova said on Friday morning.
Yelena Liptser, a lawyer for Lebedev, confirmed that Khodorkovsky's former business partner was transferred from the pre-trial facility earlier in the day. She said she was not allowed to meet with her client before his departure.
Convicts have the right to a short meeting with relatives and other individuals before they are transferred to a prison from their pre-trial detention center.
Khodorkovsky and Lebedev were convicted of stealing millions of tons of oil from Yukos and laundering the proceeds in a December trial widely condemned by Western governments and human rights groups.
A Moscow court upheld the two men's second conviction last month after they appealed and cut their sentences by one year, so they now run until 2016. The former business partners were first convicted of fraud and tax evasion in 2005. Without the second set of charges, they would have been released this year.
After their appeal against the second conviction failed, Khodorkovsky and Lebedev on Tuesday issued an appeal for release on parole. Russian human rights activists published an open letter on Thursday calling for the courts to fairly consider the parole petition.
The appeal is addressed to the chairman of Moscow's Preobrazhensky court Sergey Bogachev and to the chairman of Moscow City Court Olga Yegorova.
Khodorkovsky, once Russia's richest man, says the charges against him are revenge for his funding of opposition parties during the presidency of Vladimir Putin, a claim denied by the government.
The European Court of Human Rights said last week the ex-Yukos bosses' first trial was not politically motivated but said there were numerous violations of Khodorkovsky's conditions of detention after his arrest in October 2003.
MOSCOW, June 10 (RIA Novosti)