(CNN) Lawyers for accused Russian spy Maria Butina asked a judge Tuesday to order her removed from solitary confinement and into the general population.

Attorney Robert Driscoll said in a court filing that Butina has been held in "administrative segregation," a form of restricted housing, at an adult detention center in Alexandria, Virginia, since November 21.

Butina was previously held in solitary confinement in a Washington, DC, detention center for 22 hours a day before she was released into the general population, Driscoll said in a new court filing.

But personnel at the Virginia detention center moved her back into solitary on November 21 after Butina referred a fellow inmate to her lawyers, he wrote.

"Staff purported to base their decision to segregate on Ms. Butina referring a fellow inmate to her lawyers (that is, she gave her lawyers' phone number to a fellow inmate), but staff did not find a disciplinary violation -- major or minor," Driscoll wrote. He said he was told by supervisors that the decision was made "for her safety."

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