When Haleh Esfandiari taught Persian language courses at Princeton University throughout the 1980s and early 1990s, she brought compassion, a love of Iranian culture and an emphasis on respectful dialogue to her students.
Those traits make her detention by the government of Iran vexing to her former Princeton students, who are calling for Iranian officials to release the scholar.
Esfandiari, 67, has worked at the Washington, D.C.-based Woodrow Wilson Center for Scholars since leaving Princeton in 1994, most recently as director of the center's Middle East program.
She went to Iran late last year to visit her 93-year-old mother. On Dec. 30, her taxi was stopped on the way to the airport for her return trip, and armed men took her passport. When she tried to get a replacement passport, Iranian authorities began questioning her repeatedly, keeping her under virtual house arrest.
The situation worsened on May 8, when Esfandiari was taken to Tehran's notorious Evin Prison. Iran's judiciary said Tuesday that she is being investigated for security crimes, while Secretary of State Condoleeza Rice called for her immediate release in a rebuke of the Islamic regime.
Princeton University graduate Parinaz Vahabzadeh described Esfandiari, with whom she studied the Persian language, as a "terrific professor." Persia is the former name of Iran.
"It just saddens me that a government that should be celebrating such a scholar of the country would be throwing her in jail," said Vahabzadeh, who described Esfandiari as "almost like a mother figure" when she first came to Princeton from Canada.
Vahabzadeh, who graduated in 1993, noted that her former teacher had worked to build cross-cultural understanding, encouraging students of Persian descent to visit Iran.
Princeton University graduates are organizing a letter-writing campaign asking for her release, joining similar efforts by Amnesty International and the Web site www.freehaleh.org.
Fellow graduate Erin Logan said Esfandiari stood out in the extent to which she cared about her students, which softened her demanding expectations of students.
"She been criticized for bringing people to the U.S. to speak who are much more 'pro' the current government" of Iran, Logan said, calling the detention outrageous.
Logan said Esfandiari taught students about aspects of Persian literature and culture that are valued in the United States, such as the country's tolerance and diversity from its ancient empire through recent history.
"Her whole career has been about understanding and engagement," Logan said.
The Iranian judiciary's announcement Tuesday was the first official word on an investigation into Esfandiari, who has been living in the United States since 1980.
Asked about Esfandiari's detention, Rice said she "ought to be released immediately."
"It just underscores the nature of the Iranian regime and it just gives strength to the argument that the regime does not, in addition to all of the problems that it causes internationally, does not treat its people ... very well," Rice told reporters in Moscow, where she was meeting with Russian leaders.
Sen. Hillary Clinton, D-N.Y., and Sen. Gordon Smith, R-Ore., introduced a resolution Tuesday calling for Esfandiari's immediate release.
Over the weekend, the hard-line Iranian newspaper Kayhan said Esfandiari was accused of spying for the United States and Israel and had formed networks of activists to overthrow the Iranian government.
Her husband, Shaul Bakhash, called the accusations "fantasies" and "untrue."
Judiciary spokesman Ali Reza Jamshidi said Esfandiari was being investigated for "security" crimes, but did not give details or say what specific actions led to her arrest.
"Charges against Esfandiari are being investigated by the Intelligence Ministry ... She is being held at Evin Prison," Jamshidi told reporters Tuesday.
Esfandiari has for years brought prominent Iranians to Washington to talk about the political situation in Iran, some of whom have been subsequently detained and questioned back home. Her defenders say some of those she brought to the United States were supporters of the Iranian government who sought to explain Tehran's stance to Americans.
Her arrest came amid increasing restrictions on Iranian rights groups -- particularly women's organizations -- and other critics by the hard-line government of President Mahmoud Ahmadinejad. Iranian authorities have stepped up their warnings that the United States aims to use internal critics to destabilize the Iranian government amid the mounting tensions between the two countries.
Robert P. Finn, a lecturer at Princeton University's Woodrow Wilson School, said Iran has made a terrible mistake in arresting her.
"She's exactly the sort of person the Iranians should be supporting," he said.
Also Tuesday, Jamshidi said an Iranian journalist who was detained in December at Tehran's airport after returning from a conference in India has been sentenced to three years in prison. Jamshidi did not specify the charges against Ali Farahbakhsh, but the journalist's lawyer, Morteza Alizadeh Tabatabaei, said he was detained on charges of espionage.
Other Iranian-Americans have been prohibited from leaving Iran in recent months, including journalist Parnaz Azima, who works for the U.S.-funded Radio Farda. Another American, former FBI agent Robert Levinson, disappeared in March after going to Iran's resort island of Kish.