Mrs Behbahani is Iran's most celebrated living poet
Iran's leading female poet has told the BBC she has been barred from leaving the country by the government.
Simin Behbahani, 82, said she was about to fly to France when her passport was confiscated at Tehran airport.
The human rights activist has written poems in support of the opposition campaign against disputed elections in June last year.
Last week Iran detained international award winning film director Jafar Panahi and members of his family.
"The moment I was due to get on the plane, a man came and took my passport away from me and said that I was banned from going abroad," she told the BBC's Persian service.
They questioned her for hours asking questions and then ordered her to appear before a court, she said.
She was on her way to Paris to present a paper on feminism and read a poem at conference.
Mrs Behbahani is close to the Nobel Peace Prize winning human rights lawyer Shirin Ebadi, who has been living in exile since elections in June.
Supporters of reformist figures Mir Hossein Mousavi and Mehdi Karroubi say that the elections in June were rigged in favour of President Mahmoud Ahmadinejad.
The Iranian protest movement has developed into the biggest challenge to the government since the Islamic Revolution in 1979.
Thousands of people have been arrested and dozens killed.
Opposition supporters have faced increasing pressure from the authorities, with some hardliners labelling them as "mohareb" - enemies of God who can be sentenced to death under Iran's Sharia law.
At least nine have so far been sentenced to death and two people have reportedly been hung.