The father of American journalist Roxana Saberi said he has not heard from his daughter since she was arrested and detained in Iran almost a month ago.

“Roxana called on February 10 to say that she had been arrested on January 31,” Reza Saberi told FOX News. “She did not say why she had been arrested or what for. She could not even say where she was when she was calling.”

Saberi said his daughter, who moved to Iran six years ago and had previously reported for NPR, the BBC and FOX News, had her press credentials revoked, and was not working as a journalist.

"She said that she had bought a bottle of wine and the person that sold it had reported it and then they came and arrested her," he told NPR.

Saberi said he believes his daughter was writing a book about Iran at the time of her arrest.

Roxana, 31, told her parents not to tell anyone about what had occurred in her phone call to them 18 days ago. She said she would be released within two to three days, Saberi said.

Roxana — a former Miss North Dakota — is an American citizen who also holds an Iranian passport because her father is Iranian.

Saberi told FOX News that he had spoken with some of his daughter's friends in Tehran, but that no one has any information about what happened to her.