Hashemi had been ordered to appear before a grand jury in Washington but was not charged with a crime. Her family and Iranian leaders accused American officials of disrespecting her Muslim faith while she was under arrest, forcing her to remove her hijab, or head scarf, and offering her only non-halal food.
The F.B.I. has declined to talk about Ms. Hashemi or the grand jury case in which she had been required to testify, the New York Times reported.
Hashemi was arrested in St. Louis while on a trip to the United States to visit relatives, and was transferred by the F.B.I. to Washington. Officials later disclosed she was a material witness in an unspecified criminal case.
Hashemi, who was born Melanie Franklin in Louisiana, moved to Iran more than a decade ago, but she has periodically returned to visit family. She is well known in Iran as an anchorwoman on Press TV’s English service.