"My family threatens to kill me for the most trivial things," Alqunun told Reuters.
Asked why she was seeking refuge in Australia, she said: "Physical, emotional and verbal abuse and being imprisoned inside the house for months. They threaten to kill me and prevent me from continuing my education."
Alqunun added: "They won't let me drive or travel. I am oppressed. I love life and work and I am very ambitious but my family is preventing me from living."
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Her family could not immediately be reached for comment. In her initial social media pleas, Alqunun said her family was powerful in Saudi society but she did not identify them.
For runaway Saudi women — to whom Saudi law grants male relatives legal guardianship even if they are adults — fleeing can be a matter of life and death, and they are almost always doing so to escape male relatives.
Phil Robertson, deputy Asia director for Human Rights Watch, said: "The key thing is she should not be sent back to Saudi Arabia, she should not be sent back into harm's way."
He said Riyadh would "not give up easily" in this case, adding: "They will be worried if she succeeds then and is able to escape that she will be an inspiration to many other Saudi young women you are fed-up with the discrimination and abuses that they suffer under the guardianship system."
Alqunun appeared to have scored a small victory on Monday when the flight on which she said she would be sent to Kuwait departed without her.
Germany's ambassador to Thailand, Georg Schmidt, also posted a message of concern on his verified Twitter account about her case, which he said he was conveying to Thai authorities.
The Associated Press reached Alqunun by telephone Sunday night in her hotel room and she spoke briefly, saying that she was tricked into giving up her passport on her arrival in Bangkok.
"Someone told me he would help me get a visa for Thailand, so I can go inside," she said "After that he took my passport. After one hour he came with five or four persons and told me my family wants me. And they knew I had run away and should go back to Saudi Arabia."
Alqunun has identified the man who took her passport variously as a Kuwait Airways employee or a Saudi Embassy official. She said Saudi and Thai officials then told her she would be returned to Kuwait on Monday, where her father and brother are awaiting her.
Saudi Arabia's charge d'affaires in Bangkok Abdullah al-Shuaibi denied Saudi authorities were involved in any way.
He was quoted in Saudi press saying that Alqunun was stopped by Thai authorities because she did not appear to have a return ticket, a hotel reservation or itinerary to show she was a tourist. He said the Saudi Embassy has no authority to stop anyone at the airport and that this decision rests with Thai officials.
"She was stopped by airport authorities because she violated Thai laws," al-Shuaibi was quoted as saying in Sabq, a state-aligned Saudi news website. "The embassy is only monitoring the situation."
Alqunun's plight mirrors that of other Saudi women who have tried to flee abusive or restrictive family conditions.
A Saudi activist familiar with other cases of females who've run away said often the women are young, inexperienced and unprepared for the obstacles and risks involved in seeking asylum when they attempt to flee.
Speaking on condition of anonymity for fear of repercussion, the activist said there have been instances where Saudi women runaways were stopped by authorities in Hong Kong or the Philippines en route to Australia or New Zealand. In some cases, Saudi authorities have been involved in forcing women to return to their families and in other cases local authorities suspect the women of seeking asylum and deport them.
Alqunun appears to have attempted to flee while on a family visit to Kuwait.
Saudi Arabia requires that a woman have the consent of a male relative — usually a father or husband — to obtain a passport, travel abroad or marry.
Saudi women runaways, however, have increasingly turned to social media to amplify their calls for help.
In 2017, Dina Lasloom triggered a firestorm online when she was stopped en route to Australia where she planned to seek asylum. She was forced to return to Saudi Arabia and was not publicly heard from again, according to activists tracking her whereabouts.