There are concerns for the wellbeing of Iranian sport climber Elna Rekabi, after she competed at an event in South Korea without her nation's mandatory headscarf covering.
Rekabi left South Korea on Tuesday after coming fourth at the event, authorities said.
Farsi-language media outside of Iran warned she may have been forced to leave early by Iranian officials and faced arrest back home.
The decision by Rekabi, a multiple medallist in various competitions, to forgo the headscarf, or hijab, came as protests sparked by the September 16 death in custody of 22-year-old woman Mahsa Amini entered their fifth week.
Ms Amini was detained by the country's morality police over her clothing.
The demonstrations, drawing school-aged children, oil workers and others to the street, represent the most serious challenge to Iran's theocracy since the mass protests surrounding its disputed 2009 presidential election.
Rights groups say hundreds of people have been killed as authorities crack down on the protests. Amnesty International says at least 23 children have died.
Phone and passport reportedly seized
Rekabi left Seoul on a Tuesday morning flight, the Iranian embassy in South Korea said. The BBC's Persian service, which has extensive contacts within Iran despite being banned from operating there, quoted an unnamed "informed source" who described Iranian officials as seizing both Rekabi's mobile phone and passport.
BBC Persian also said she initially had been scheduled to return on Wednesday, but her flight apparently had been moved up unexpectedly.
The BBC also said friends of Rekabi had not been able to contact her since she competed.
IranWire, another website focusing on the country founded by Iranian-Canadian journalist Maziar Bahari, who was once detained by Iran, alleged that Rekabi would be immediately transferred to Tehran's notorious Evin Prison after arriving in the country.
Evin Prison was the site of a massive fire this weekend that killed at least eight prisoners.
In a tweet, the Iranian embassy in Seoul denied "all the fake, false news and disinformation" regarding Rekabi's departure on Tuesday.
But instead of posting a photo of her from the Seoul competition, it posted an image of her wearing a headscarf at a previous competition in Moscow, where she also took a bronze medal.
Calls to the Iranian embassy in Seoul went unanswered on Tuesday.
Rekabi normally competes with hijab
Rekabi didn't put on a hijab during Sunday's final at the International Federation of Sport Climbing's Asian Championships, according to the Seoul-based Korean Alpine Federation, the organisers of the event.
Federation officials said Rekabi wore a hijab, as she normally does, during her initial appearances at the one-week climbing event.
The event doesn't have any rules on requiring female athletes to wear or not wear headscarves. However, Iranian women competing abroad under the Iranian flag always wear the hijab.
The International Federation of Sport Climbing released a statement on Tuesday saying it was "fully aware" of the stories about Rekabi's situation and it was trying to establish the facts.
"We have also been in contact with Ms Rekabi and the Iranian Climbing Federation," the statement said.
"Our understanding is that she is returning to Iran, and we will continue to monitor the situation as it develops on her arrival.
"It is important to stress that athletes' safety is paramount for us and we support any efforts to keep a valued member of our community safe in this situation.
"The IFSC fully support the rights of athletes, their choices, and expression of free speech."
Rekabi, 33, has finished on the podium three times in the Asian Championships, taking one silver and two bronze medals for her efforts.
Athletes speaking out to back protests
Australian Olympic climbing representative Oceania Mackenzie labelled Rekabi "a hero" on Instagram, and was one of a number of people within the climbing community who praised her bravery.
It is also not the first time athletes have used their platforms in recent months to protest the treatment of women in Iran and support the demonstrations there.
Razieh Janbaz, a star of the Iranian handball team, resigned from the national set-up over the issue, while Iranian-born Australian footballer Daniel Arzani held up a shirt with Amini's name on it after scoring for Melbourne City in their A-League win over Adelaide on the weekend.
ABC/AP
