An Iranian-American academic imprisoned for months before being released on bail in August was permitted to leave Iran after authorities gave back her passport, her lawyer and family said Monday.

Haleh Esfandiari, 67, was able to pick up her passport Saturday and flew the next day from Iran to Austria, where her sister lives, said her daughter, Haleh Bakhash.

She plans to stay in Austria, where she will be reunited with her husband, for a week before heading home to the United States, Bakhash said.

"She had some indication that she would get her passport back but she didn't know when. It was a complete surprise to all of us, and a relief," Bakhash told The Associated Press on the telephone from her home in Washington, D.C.

The unexpected development came after Iranian President Mahmoud Ahmadinejad said last week that his government was not opposed to Esfandiari leaving the country, but her case was a legal issue that had to be sorted out with the Iranian judiciary.

Though Esfandiari got back her passport, which authorities first seized in January, her daughter was unclear whether charges against her remained.

"We don't know where any of that stands. We know she is free to go and got her passport back," Bakhash said.

Her lawyer in Iran, Abdol Fattah Soltani, told The Associated Press that Esfandiari got her passport and left Iran afterward, but he had no more details.

Last month, another lawyer for Esfandiari, Nobel Peace Prize laureate Shirin Ebadi, said there was no legal obstacle standing in the way of her client rejoining her family back in the United States, but she has to return to Iran to stand trial over charges of endangering national security.

Esfandiari, who is the head of the Middle East program at the Woodrow Wilson International Center for Scholars, was released on bail Aug. 21 from Tehran's notorious Evin prison where she was held since May. Her 93-year-old mother used the deed to her Tehran apartment to post bail.

Iranian judiciary officials have not provided answers on Esfandiari's legal status since the release. She may still have to stand trial or have to return to Iran to appear in court.

The Iranian Intelligence Ministry had accused her and her organization of trying to set up networks of Iranians with the ultimate goal of creating a "soft revolution" in Iran. Her family and the Wilson Center have denied the allegations.

Esfandiari was one of a handful of Iranian-Americans detained or facing security-related charges here. The detentions have sharply added to tensions between the United States and Iran.

Washington accuses Iran of arming Shiite Muslim militants in Iraq and seeking to develop nuclear weapons. Tehran denies those claims, and blames the U.S. for Iraq's instability.

Esfandiari was detained Dec. 30 after three masked men holding knives threatened to kill her on her way to Tehran's airport to fly back to the U.S. from a visit to her mother, the Wilson Center has said.

For weeks, she was interrogated by authorities for up to eight hours a day about the activities of the Center's Middle East Program, the Washington-based foundation said.

She was charged in May, and for months, her only contact with her family were brief telephone calls to her mother in which she said she was under stress. Since her release on bail, Esfandiari is believed to have stayed at her mother's home in Tehran.

"She called when she arrived in Vienna at the airport, and it was so good to hear her voice. She sounded very happy," her daughter said.

A phone message left by the AP with the Wilson Center was not immediately returned Monday.

Iran has charged three other Iranian-Americans with security-related offenses: Parnaz Azima, a journalist for U.S.-funded Radio Farda; Kian Tajbakhsh, an urban planning consultant with the Soros Foundation's Open Society Institute; and Ali Shakeri, a founding board member of the Center for Citizen Peacebuilding at the University of California, Irvine.

Shakeri and Tajbakhsh are in prison; Azima is free but barred from leaving Iran. No other details about the circumstances of the three are known for now.

In July, Iran's state television broadcast a video in which Esfandiari said a network of foreign activists was trying to destabilize Iran and bring about "essential" social change. Tajbakhsh, who also featured in the video, said that his organization tried to create a "gap between the government and the nation."

The Wilson Center and the Open Society Institute criticized the Iranian government for the broadcast and dismissed the statements as "coerced."

After her release on bail in August, Esfandiari was shown on Iranian state television walking out of the prison, visibly thinner and gaunt, and meeting relatives in a car on a nearby street.

At the time, she told her family she was treated well in prison, but was kept in solitary confinement in a cell with one window and was on a strict regimen, pacing the room for exercise.