Russian police on Sunday briefly detained journalist Marina Ovsyannikova, a state television producer who staged an anti-war protest live on air in March, and charged her with "discrediting" the Russian military.
No official statement has been made, but her detention comes a few days after 44-year-old Ovsyannikova demonstrated alone near the Kremlin holding a placard criticizing Russia's intervention in Ukraine and President Vladimir Putin.
"Marina has been detained," her entourage said in a message posted on the journalist's Telegram account. "There is no information on where she is."
The message included three photos of her being led by two police officers to a white van, after apparently having been stopped while cycling.
Her lawyer, Dmitry Zakhvatov, confirmed her arrest to the state-run RIA Novosti news agency, saying he did not know where Ovsyannikova had been taken.
"I assume that it is linked one way or another to her act of protest," he added.
Police released Ovsyannikova three hours later, the journalist herself told the independent news Telegram channel Mozhem Obyasnit.
Ovsyannikova said she has been charged with "discrediting" the Russian military during last week's trial of opposition activist and former municipal deputy Ilya Yashin, where she had turned up with other journalists and activists in his support.
On Friday, Ovsyannikova posted photos of herself on Telegram showing her near the Kremlin and carrying a protest placard raising the deaths of children and denouncing Putin as a "killer."
Declarations of this kind expose her to criminal prosecution for publishing "false information" about and "denigrating" the army, offenses that can carry heavy prison sentences.
She now faces a fine of 50,000 rubles ($900) under the administrative charges of discrediting the military's actions, according to Avtozak Live, a Telegram channel that tracks detentions across Russia.
Ovsyannikova became internationally famous overnight in March when she staged her live TV protest, holding a poster reading "No War" in English during the flagship evening news program Vremya (Time) at Channel One television, where she had served as editor. Pictures of her interrupting the broadcast went around the world.
She was briefly detained and then released with a fine, but while a number of international observers praised her protest, it was not universally acclaimed by Russia's opposition.
Some critics said that she had spent years working for Channel One, which they said was effectively a mouthpiece for the Kremlin.
In the months following her March protest, Ovsyannikova spent some time abroad, including a brief period working for the German newspaper Die Welt.
In early July, she announced that she was returning to Russia to settle a dispute over the custody of her children.
AFP contributed reporting.