The lawyer of an Iranian-American academic, who spent three months in jail in Tehran, said Monday that she had left Iran overnight.
Esfandiari, 67, was released on bail Aug. 21 from the Iranian capital'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.
In the United States, Esfandiari's husband, Shaul Bakhash, and her employer, the Washington-based Wilson Institute, were not immediately available for comment.
The unexpected development followed comments by Iranian President Mahmoud Ahmadinejad, who last week said that his government was not opposed to Esfandiari leaving the country but that this was a judicial issue that had to be sorted out with the Iranian judiciary.
However, at the time Esfandiari had no passport to leave Iran since authorities seized it in January.
Soltani said that Esfandiari got her passport on Sunday and left Iran afterward, but had no more details.
Nobel Peace Prize laureate Shirin Ebadi, another lawyer for Esfandiari, said last month that there was no legal obstacle in the way of Esfandiari 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 is the head of the Middle East program at the Woodrow Wilson International Center for Scholars.
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 husband and the Wilson Center have denied the allegations.
Esfandiari was one of a handful of Iranian-Americans detained or facing security-related charges here, adding 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.