American-born Marzieh Hashemi is a news anchor for  Iran's state-funded Press TV.
CNN  — 

An Iranian journalist whose arrest in the United States this month under mysterious circumstances drew rebukes from the highest levels of the Iranian government has been released from US custody after testifying before a federal grand jury in Washington, two people familiar with her case said.

Marzieh Hashemi, an anchor for Iran’s state-funded Press TV, had been held as a material witness since flying into the St. Louis airport 10 days ago. She has not been charged with a crime.

“Everybody’s relieved that she’s been released, but there’s concern and anger at the way this was handled,” said Abed Ayoub, the legal and policy director of the American-Arab Anti-Discrimination Committee, a group that has been advising Hashemi’s family.

Hashemi, who was born in the United States as Melanie Franklin, testified Wednesday before a grand jury that’s investigating an unknown case, Ayoub said.

Members of her family said they had also been subpoenaed to testify before the grand jury, though it is unclear if they did so.

Hashemi was in St. Louis to film a documentary on Black Lives Matter for Press TV, her son, Hossein Hashemi, had told CNN earlier. He said he did not know why his mother had been detained.

CNN has reached out to the Department of Justice. The FBI earlier had declined to comment on Hashemi’s detention.

In a filing last week, the court revealed that Hashemi was being held under the obscure material witness statute. The government expected to release her “immediately following the completion of her testimony before a grand jury investigating violations of US criminal law,” the filing said.

The material witness statute has been used little in recent years but was employed in the aftermath of the September 11 terror attacks. It allows officials to order the arrest of a person who is “material in a criminal proceeding” if there is evidence that it may be difficult to force him or her to appear in a US court.

Iranian Foreign Minister Javad Zarif had demanded Hashemi’s release last week.

“The custody of Iran’s reporter in the US is highly political and she should be released immediately,” Zarif said, according to the state-run Islamic Republic News Agency, or IRNA.

“The misbehavior of the US government indicates that the US does not abide by any principles protecting rights of those criticizing the system and is now turned to a dangerous country for reporters.”

On Tuesday, Iran’s Foreign Ministry summoned the Swiss ambassador to Tehran, a proxy for Washington, to express displeasure with the length and circumstances of Hashemi’s detention, Iran’s state media reported.