A Moscow court ordered the mother of three be released on parole on Tuesday, but her lawyer Roman Golovkin said she was still in detention.
"Svetlana is still there waiting for the documents for her release to arrive," Golovkin said.
He said that her husband Mikhail also had no information on her release, adding that he hoped she would be released in the course of the day.
Bakhmina, 39, was still to serve a little more than two years of her 6-1/2-year prison term. She gave birth to a daughter last November while in prison. Her parole appeals had been turned down by a court in the Volga republic of Mordovia, where she served her sentence, several times before.
Bakhmina's case has attracted much attention, with Kremlin critics saying Bakhmina was a political prisoner along with other Yukos executives in what they call a politically motivated crackdown on the oil giant and its now jailed founder Mikhail Khodorkovsky.
