An American-born journalist based in Tehran asserted Friday that her arrest without charge by U.S. authorities was related to her work for Iran’s state-funded English-language satellite television channel but declined to comment on the focus of the criminal investigation and what she was asked by a grand jury.

Marzieh Hashemi, 59, a producer and on-air presenter for Iran’s Press TV, told reporters her nine-day detention this month under a “material witness” warrant and subsequent testimony before a U.S. grand jury in a sealed case was “related to where I live, and to what I do.”

Hashemi declined to say whether her questioning by U.S. prosecutors suggested they are examining whether Press TV, sponsored by Iran’s state-run television operation, Islamic Republic of Iran Broadcasting, may have violated disclosure requirements under the Foreign Agents Registration Act for anyone advocating in the United States on behalf of a foreign government or political party.

She also said she could not address whether investigators were looking into other Iran-related matters, such as a sanctions-violation case or alleged crimes by an individual.

Hashemi, appearing with demonstrators outside the federal courthouse in Washington protesting her arrest, said journalists for foreign state-run media should take heed of what she called an attempt by the American government to intimidate an outlet presenting opposing views.

“Make no mistake. They can call it whatever they want to call it, but I was kidnapped,” Hashemi said in describing her arrest to about 80 protesters, including members of CodePink, Louis Farrakhan’s Nation of Islam and local African American Muslim advocates.

Hashemi linked her arrest to her broadcasts about racial and anti-Islamic bias in American society, saying: “We will not be intimidated. We will not back off the truth, no matter the price.”

Hashemi, a dual U.S.-Iranian citizen who has worked in Iran for about 25 years, was arrested this month upon arriving at Lambert International Airport in St. Louis, where she had been working on a documentary about Black Lives Matter, before boarding a flight to Denver to visit her adult children in Colorado, her family said.

The U.S. government, in a court order unsealed Jan. 18, confirmed it was holding Hashemi, who also was referred to by her birth name of Melanie Franklin in the court filing, pending testimony in a sealed criminal matter, and that she was not accused of any crime. She was arrested under a material-witness warrant.

Material-witness warrants are rare and can be used to arrest witnesses if they have information important to a criminal investigation and are deemed likely to flee.

Hashemi was released from U.S. custody Tuesday and completed her testimony the following day, closing the matter,, according to a second unsealed order by Chief U.S. District Judge Beryl A. Howell of the District of Columbia.