BBC: Iran's foreign ministry has confirmed that the government has detained a leading Iranian-American academic.
Spokesman Mohammad Ali Hosseini said the arrest of Haleh Esfandiari was lawful and she would be treated like other Iranian nationals.
Ms Esfandiari, one of Washington's best known Iran experts, was visiting Tehran to see her 93-year-old mother.
The incident comes at a time of continuing tension between the United States and Iran.
"It is natural if there is any problem, it will be handled by authorities," said the spokesman.
Iran does not recognise dual nationalities.
Iran admits detaining US academic (more)
Mark Alexander
