The Swiss ambassador to Tehran has been summoned over the detention of a U.S.-born Iranian television anchor in the United States.
Foreign Ministry spokesman Bahram Qasemi said on January 22 that Iran asked the envoy for the immediate release of Marzieh Hashemi, who works for Iran's state-run English-language Press TV news channel.
The Swiss Embassy represents U.S. interests in Tehran.
Hashemi's son has said she was detained by federal agents on January 13 in St. Louis, Missouri, where she had filmed a Black Lives Matter documentary.
She was then transported to Washington and has been in custody since then.
According to federal court documents made public on January 18, Hashemi was detained as a material witness, though it is unclear for which case.
Officials said she was expected to be released immediately after her testimony is completed, but it's not clear when that would be.
Qasemi said that the handling of the case and the "questionable silence" of the U.S. authorities was a breach of human rights and a violation of the United States' international commitments.
Iranian Foreign Minister Mohammad Javad Zarif has condemned Hashemi's detention as a "violation of freedom of speech."
In a January 21 statement, Reporters Without Borders (RSF) has condemned the "opaqueness" surrounding Hashemi's detention.