A Washington-based academic arrested in Tehran last week is being investigated by the Intelligence Ministry for suspected "crimes against national security", Iranian judiciary officials said on Tuesday.
Haleh Esfandiari, the director of the US Woodrow Wilson International Center for Scholars' Middle East program, was detained on May 8 and taken to Tehran's Evin prison, the centre and her family said last week.
It took place at a time of rising tension between Washington and Tehran over Iran's nuclear programme, which the West suspects is aimed at making atom bombs. The two foes have not had diplomatic ties since after Iran's 1979 Islamic revolution.
The United States has condemned the arrest of Esfandiari, who has dual US and Iranian citizenship, and said she was among a number of US-Iranians being detained by Tehran.
"She is right now under the authority of the Intelligence Ministry," judiciary spokesman Ali Reza Jamshidi told reporters, confirming Esfandiari was being held in Evin. Jamshidi did not give details but a judiciary source later told Reuters Esfandiari was held on suspicion of "crimes against national security", a broad legal term covering acts deemed to endanger the stability of the Islamic state.
Terrorism, spying and stirring political unrest are examples of crimes falling within this category under Iranian law. The charge could carry the death sentence.
Esfandiari's arrest and detention revealed "the nature of the Iranian regime", US Secretary of State Condoleezza Rice said. "She ought to be released and she ought to be released immediately," Rice told reporters in Moscow.
Iran researcher Hadi Ghaemi of US-based Human Rights Watch, which has called for Esfandiari's immediate release, said Iranian authorities in the past had charged hundreds of dissidents and critics with "acting against national security." "This is a vaguely defined charge that provides a very easy means for the judiciary to detain and interrogate people," he said. "It is usually based on people's writing and opinion which by no means constitutes acting against national security."