A young Saudi woman says she is stranded at Bangkok's main airport after fleeing her family and having her passport seized by a Saudi official.
Rahaf Mohammed al-Qunun, 18, says she was on a trip to Kuwait with her family when she fled on a flight two days ago.
She was trying to head to Australia via a connecting flight in Bangkok.
She told the BBC that she had renounced Islam, and feared she would be forcibly returned to Saudi Arabia and killed by her family.
The BBC's Jonathan Head in Bangkok says Ms Mohammed al-Qunun is frightened and confused. She says she has an Australian visa but her passport was seized by a Saudi diplomat when he met her coming off the flight at Suvarnabhumi airport.
My name is Rahaf Mohammed Mutlaq Alqunun, and this is my picture pic.twitter.com/RHsnnPWUjL— rahaf Mohameed (@rahaf84427714) January 6, 2019
A Saudi envoy in Bangkok denied any official Saudi involvement in Ms Mohammed al-Qunun's detention.
"The embassy does not have the authority to arrest (anyone) at the airport or elsewhere," Abdellilah al-Shaayibi told news website Sabq. "She was stopped by airport authorities because she violated Thai laws".
Thai police Maj Gen Surachate Hakparn told the BBC that Ms Mohammed al-Qunun was escaping a marriage. Because she did not have a visa to enter Thailand, he said police had denied her entry and were in the process of repatriating her through the same airline she had taken, Kuwait Airways, by Monday morning.
Gen Surachate said he was unaware of any passport seizure.
He told AFP the case was a "family problem" and the teenager "had no further documents such as [a] return ticket or money".
However, Human Rights Watch Asia deputy director Phil Robertson told the BBC: "It seems that the Thai government is manufacturing a story that she tried to apply for a visa and it was denied... in fact, she had an onward ticket to go to Australia, she didn't want to enter Thailand in the first place."
He argued that the Thai authorities had clearly co-operated with Saudi Arabia as Saudi officials were able to met the plane when it arrived.
Ms Mohammed al-Qunun told BBC Newshour she was now in a hotel in the transit area.
She said: "I shared my story and my pictures on social media and my father is so angry because I did this... I can't study and work in my country, so I want to be free and study and work as I want."
Ms Mohammed al-Qunun wrote on Twitter that she had decided to share her name and details because she had "nothing to lose" now.
She also shared a picture of her passport "because I want you to know I'm real and exist".
Another tweet read: "I'm afraid my family will kill me."
The case echoes that of another Saudi woman who was in transit to Australia in April 2017.
Dina Ali Lasloom, 24, was en route from Kuwait via the Philippines but was taken back to Saudi Arabia from Manila airport by her family.
She used a Canadian tourist's phone to send a message, a video of which was posted to Twitter, saying her family would kill her.
Her fate on arriving back in Saudi Arabia remains unknown.