Azima was already facing charges of working with Radio Farda and spreading propaganda against the Iranian state.
Azima and her lawyer, Mohammad Hossein Aqasi, have rejected the charges as baseless.
Aqasi told Radio Farda that authorities have given Azima no indication of when she might be allowed to leave.
"Officials who decide about the case -- apart from judiciary officials -- have emphasized that she should stay in Iran for now. The reason they mention is her special situation in international relations -- in fact, that means ties between Iran and the U.S.," Aqasi said.
Azima traveled to Tehran in January to visit her sick mother. On her arrival, authorities confiscated her Iranian passport.
Since then, Azima has been unable to leave Iran and return to her work in Prague.
In an August 27 telephone interview with Radio Farda, Azima described her situation as "unbearable."
"This uncertain situation is very difficult to deal with. I left all my life abroad to come and visit my ailing mother, and now I feel my personal life is falling apart," Azima said. "My grandchild will be born soon in the U.S., and I wish I could be there to experience it. I was under medical treatment before coming to Iran, and that has now been interrupted."
Azima said that authorities had urged her to resign from Radio Farda, but she told them that her work was her own decision.