A prominent American anchorwoman on Iranian state television has been arrested by the FBI during a visit to the US, the broadcaster reported Wednesday, and her son said she was being held in a prison, apparently as a material witness.Marzieh Hashemi, who worked for the network’s English-language service, was detained in St. Louis, where she had filmed a Black Lives Matter documentary after visiting relatives in the New Orleans area. She was then taken to Washington, according to her elder son, Hossein Hashemi. The FBI said in an email that it had no comment on the arrest of the woman who was born Melanie Franklin in New Orleans and has worked for Iran’s state television network for 25 years.Hossein Hashemi said his mother lives in Tehran and comes back to this country about once a year to see her family, usually scheduling documentary work somewhere in the US as well. “We still have no idea what’s going on,” said Hashemi, a research fellow at the University of Colorado who was interviewed by phone from Washington. He also said he and his siblings had been subpoenaed to appear before a grand jury.The incident comes as Iran faces increasing criticism of its own arrests of dual citizens and other people with Western ties. Those cases have previously been used as bargaining chips in negotiations with world powers. Federal law allows judges to order witnesses to be arrested and detained if the government can prove 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.Marzieh Hashemi, an American citizen, had not been contacted by the FBI before she was detained and would “absolutely” have been willing to cooperate with the agency, her son said. Asked whether his mother had been involved in any criminal activity or knew anyone who might be implicated in a crime, Hashemi said, “We don’t have any information along those lines.”Hashemi said his mother was arrested as she was about to board a flight from St. Louis to Denver. A spokesman for St. Louis Lambert International Airport declined to comment and referred questions to the FBI. The constitutionality of the material witness law has “never been meaningfully tested,” said Ricardo J. Bascuas, a professor at the University of Miami School of Law. “The government only relies on it when they need a reason to arrest somebody but they don’t have one.”No matter the reason for Marzieh Hashemi’s detention, she should have been granted a court appearance by now, Bascuas said.Published in Daily Times, January 18th 2019.