A British human rights lawyer says the former wife of a nephew of the ruler of Dubai has gone missing.
Contact with Zeynab Javadli was lost on Tuesday and the BBC has been told her home in Dubai is locked and empty.
Javadli has repeatedly expressed concern for her safety. She's been embroiled for years in a bitter custody battle with her ex-husband, Sheikh Saeed bin Maktoum bin Rashid Al Maktoum.
The BBC has contacted a number of officials in the UAE for comment but has received no response as of yet.
Friends of Javadli raised the alarm when their phone calls and messages received no reply on Tuesday.
The British lawyer and activist, David Haigh, said he last spoke to Javadli on Tuesday night. Since that moment, he said, she has "vanished".
Neither she nor her three young daughters have been seen or heard from since.
He told the BBC no-one in authority has given a "single answer" as to what might have happened to her.
Javadli's mother - who had just arrived in Dubai for a visit - has since gone to her house and found it empty, with the locks changed.
She is understood to have been in touch with police in Dubai and the consulate of Azerbaijan - the country Javadli is from.
For months, Javadli had barely left the house as she believed security officers were waiting to take her children from her and possibly put her under arrest.
Last year, her ex-husband lodged a complaint with the police accusing her of kidnapping their daughters, in the latest development of their bitter custody dispute.
That was after the children changed hands between their parents several times, with each accusing the other of kidnap.
Javadli - who is a former international gymnast - has also been facing potential arrest for e-crimes - online offences - in the UAE after she livestreamed one of the showdowns last year.
At the time she explained her actions in a video message to Haigh, who's been advocating for her: "I knew that it was the last chance to be with my children as they would never let me see them again. I genuinely believed that it was my last chance, so I just opened a livestream and called for help."
Lawyers acting for Javadli's former husband, Sheikh Saeed bin Maktoum bin Rashid Al Maktoum, have claimed in court hearings in the custody case over their children that she was an unfit mother who had failed to send her daughters to school, was living in a place unsuitable for the children when she was in a hotel, and that she had put the health of the youngest girl at risk.
Javadli rejected the accusations and her Emirati legal team submitted evidence to the contrary in court.
Haigh says the current situation bears a "deeply troubling resemblance" to five years ago, when his communications were cut off with Princess Latifa, one of the daughters of the ruler of Dubai, Sheikh Mohammed bin Rashid Al Maktoum.
Princess Latifa mounted a bid for freedom in 2018 from what at the time she claimed was her family's coercive control.
The boat on which she was making her escape was intercepted in the Indian Ocean and she was forcibly returned to Dubai. She then claimed she was being held captive in secret videos.
She has since re-emerged to a limited extent in public, saying she was well and living as she wished.
Haigh, who campaigned at the time for Princess Latifa, said he has issued an urgent call for the international community to demand confirmation of Javadli's whereabouts and welfare.
