An American-born Iranian television anchor has been arrested as a material witness in a federal probe, a federal court order said Friday. The arrest of Marzieh Hashemi, an anchor for Iran’s English-language Press TV news channel, has fueled tensions in already strained ties between Tehran and Washington. The order, which approved the partial unsealing of information in the case, said Hashemi was arrested on a material witness warrant issued by a federal judge and that she was assigned an attorney but “has not been accused of any crime.” It did not disclose further details of the case. Hashemi has made two court appearances, and the US government expects her immediate release after she finishes testifying before a federal grand jury investigating violations of US criminal law, the order continued. Iran has called for the immediate release of Hashemi, who state-run Press TV said was arrested on Sunday by the FBI at St. Louis Lambert International Airport. Press TV on Saturday quoted Hashemi’s son as saying US officials had banned family members from speaking to media. The television did not give further details and the report could not be immediately confirmed. The FBI and the Justice Department declined to confirm her arrest or comment on the case. A US government source told Reuters it appeared that the grand jury was examining whether Press TV is a propaganda outlet that failed to register with the Justice Department as an agent of a foreign government. Press TV said on Wednesday that Hashemi was born Melanie Franklin in the United States and changed her name after converting to Islam. Iranian Foreign Minister Mohammad Javad Zarif was quoted by the ISNA news agency as saying that Hashemi received Iranian citizenship after marrying an Iranian.