WASHINGTON: An American-born Iranian television anchor has been arrested as a material witness in an undisclosed US federal investigation, according to a federal court order granted on Friday. At the request of the Justice Department, US District Judge Beryl Howell issued the order, the first official US confirmation of reports of the arrest of Marzieh Hashemi, an anchor for Iran's English-language Press TV news channel.

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". 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.

It did not disclose further details of the case, which has added to tensions between the Iranian and US governments over the US withdrawal from the Iran nuclear deal, the reimposition of harsh US sanctions, and the detention of Iranian-American dual nationals by Iran. 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 on a visit to see an ailing family member.

Press TV yesterday 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. Press TV quoted Hashemi's daughter as saying the anchor had been given "a hijab (Muslim head covering) and food to get by" after it had earlier said prison officials had taken a photograph of her without her hijab and had not provided halal food.

Press TV said Hashemi was due to appear before a grand jury on Jan 23. The reports 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 Hashemi received Iranian citizenship after marrying an Iranian.

She has produced documentaries critical of US policy in the Middle East and the country's treatment of Muslims and African Americans. Iran, generally on the receiving end of criticism by the United States on press freedom and human rights, pledged to defend Hashemi, who it considers an Iranian citizen due to her marriage. "The arrest of Marzieh Hashemi by America is an unacceptable political act that tramples on freedom of speech," Zarif said Wednesday.

The New York-based Committee to Protest Journalists voiced concern earlier Friday about the arrest, saying that the United States needed to disclose the reason for her arrest. The advocacy group said that Iran is detaining at least eight journalists over their work. In one of the most notorious cases, Iran detained Washington Post journalist Jason Rezaian for 544 days before he was freed as part of a reconciliation deal with President Barack Obama's administration. - Agencies