An Iranian woman detained after defiantly taking off her headscarf and holding it on a stick in Tehran has been freed, a human rights lawyer says.
The woman - whose name remains unknown - became the face of protests in the country in December, and images of her were widely shared on social media.
Iranian officials have so far made no public comments on the issue.
Meanwhile, images of another three women repeating the act have gone viral after appearing on social media.
The three unidentified women were also protesting in the capital - one at what appeared to be the same spot as the woman pictured in December.
What did the lawyer say about the protester?
Nasrin Sotoudeh said she had seen an official dossier that showed the woman had been released.
"The girl of the Enghelab Avenue has been released", Mrs Sotoudeh, a former political prisoner, wrote in a post on her Facebook page (in Persian) on Sunday.
She was referring to the avenue where the woman took off her headscarf - a punishable offence in Iran.
The lawyer said she had gone to the prosecutor's office to follow up the woman's case and had learned of her release the previous day.
"I hope they don't fabricate a legal case to harm her for using her basic rights," Mrs Sotoudeh wrote. "She has not done anything wrong to deserve prosecution."
The woman is believed to be the 31-year-old mother of a toddler.
How have Iranians reacted?
The woman has been the subject of a social media campaign in Iran following the anti-establishment protests at the end of last year in which at least 20 people died.
A hashtag in Persian asking about her whereabouts - and English-language equivalents #where_is_she and #WhereIsShe - have been used thousands of times on Twitter, as well as on other social media channels used in the country where dissent is often met with repression.
The photograph of the woman was first widely used in connection to the White Wednesday campaign in which women in Iran wear white to protest against the country's strict dress code.
Since the Iranian revolution in 1979, women have been forced to cover their hair according to Islamic law on modesty.