An American-born journalist working for Iran’s state television service was released from jail Wednesday evening in Washington, D.C., 10 days after she was arrested, her family said.

Marzieh Hashemi, 59, was detained on Jan. 13 in St. Louis where she had been filming a Black Lives Matter documentary, her son, Hossein, told The Associated Press. He added that she'd been visiting family in New Orleans before heading to St. Louis.

After she was detained, Hashemi was transferred to Washington where she appeared before a U.S. District judge at least two times while in custody.

AMERICAN ANCHORWOMAN WORKING FOR IRAN’S STATE TV ARRESTED AFTER FLYING TO U.S., BROADCASTER SAYS

While it was not entirely clear why she was detained, court documents showed she was named as a witness in a criminal case and would be released immediately after her testimony before a grand jury, the AP reported. The documents did not indicate what the case was. Federal law allows judges to order witnesses to be detained if the government can prove that their testimony has extraordinary value for a criminal case and that they would be a flight risk and unlikely to respond to a subpoena.

Her son said he did not have any information that would indicate his mother had been involved in any criminal activity or if she knew anyone who would be. "We don't have any information along those lines."

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Marzieh Hashemi, a U.S. citizen born Melaine Franklin, lives in Tehran but travels to the U.S. every year to visit family, her son said.

Iran has faced increasing criticism of its own arrests of dual nationals and others with Western ties, previously used as bargaining chips in negotiations with world powers.

Fox News' Travis Fedschun and The Associated Press contributed to this report.