Marzieh Hashemi, 59, was released from jail in Washington after being detained for 10 days, according to Abed Ayoub, an attorney with the American-Arab Anti-Discrimination Committee.
Hashemi, who works for the Press TV network's English-language service, was detained by federal agents Jan. 13 in St. Louis, Missouri, where she had filmed a Black Lives Matter documentary after visiting relatives in the New Orleans area, her son said. She was then transported to Washington and had remained behind bars since then.
Hashemi appeared at least twice before a U.S. District judge in Washington, and court papers said she would be released immediately after her testimony before a grand jury. Court documents did not include details on the criminal case in which she was named a witness.
Federal law allows judges to order witnesses to be detained if the government can prove that their testimony has extraordinary value for a criminal case and that they would be a flight risk and unlikely to respond to a subpoena. The statute generally requires those witnesses to be promptly released once they are deposed.
A person familiar with the matter said Hashemi had fulfilled her obligation as a material witness and was released. The person was not authorized to discuss the matter publicly and spoke to The Associated Press on condition of anonymity.
Hashemi is a U.S. citizen and was born Melanie Franklin. She lives in Tehran and comes back to the United States about once a year to see her family, usually scheduling documentary work in the U.S., her son said.
Her son, Hossein Hashemi, didn't immediately respond to a call seeking comment on Wednesday.
Press TV issued a statement Wednesday, saying, "Marzieh Hashemi and her family will not allow this to be swept under the carpet. They still have serious grievances and want answers as to how this was allowed to happen. They want assurances that this won't happen to any Muslim - or any other person - ever again."
The network said Hashemi would remain in Washington for a protest Friday.
Earlier Wednesday, dozens of activists protested outside the federal courthouse in Washington, where Hashemi was scheduled to appear before the grand jury. They held signs and chanted, "Free, free, Marzieh!" and "Shame, shame, USA!"