Narges Kalhor, the daughter of Ahmadinejad's adviser on cultural and media affairs, submitted her asylum application to authorities in southern Germany, Nuremberg Human Rights Film Festival spokesman Matthias Rued said.
Her father, Mahdi Kalhor, has been seen as a close ally of Ahmadinejad since early this decade.
In an interview with fellow Iranian filmmaker Hana Makhmalbaf posted on YouTube on Monday, Narges Kalhor said she did not believe her father knew about her plans.
"I'm certain he hasn't seen my film or know about this festival or where I am," she said. "I came from my own desire, for cinema, and I have to continue."
Narges Kalhor had been at the Nuremberg festival to present her film "Darkhish," or "The Rake," which condemns the use of torture and the barbarity of totalitarianism.
Mahdi Kalhor told Iran's official IRNA news agency that he knew nothing about details of his daughter's films or her plans to leave the country.
He blamed the Iranian opposition for supporting her attempts to challenge the government.
"This issue is one of the symbols of a media and soft war that opposition has launched," the agency quoted Mahdi Kalhor as saying.
He also told IRNA he had divorced Narges' mother a year ago over differences of opinion, saying she was a zealous opponent of Ahmadinejad. Narges had been living with her mother.
In the video, Narges Kalhor appears wearing a green scarf _ the color of the Iranian opposition _ draped about her neck and expresses support for the reform movement.
She said that, while she and her father have differing opinions, she hoped he would support her and possibly even change his mind.
"Any moment, a person can change," Narges Kalhor said. "At any time, a person can have a moment of calm and think about what the correct path is."
"Just a little solitude can open our eyes to the world and we can decide, this is the correct path, the path of these millions of people who went to the streets asking for freedom."
Lee Keath contributed from Cairo.