Her fate on arriving back in Saudi Arabia remains unknown.
Despite that, a tweet showing text messages from Ms Alqunun to friends claims the staff members attempted to force her onto a flight.
The incident comes against the backdrop of intense scrutiny of Saudi Arabia over its investigation and handling of the shocking murder of journalist Jamal Khashoggi a year ago, which has renewed criticism of the kingdom's rights record.
She added that she was certain she will be imprisoned if she is sent back.
The young woman said she had been abused by her family and would be killed if she returns home.
"Please I need u all", she wrote.
Rahaf said she had been suffering beatings and emotional abuse from her family members according to media reports. A spokesman for Kuwait Airways said he had no information about the case. She later said that she had barricaded herself in her hotel room until she could see officials from the UN High Commissioner for Refugees (UNHCR).More news: Lady Gaga, 'Roma' shine at nice over nasty Golden Globes
But Human Rights Watch said Thai authorities must allow the teenager to make a refugee claim with UNHCR, the United Nations refugee agency.
A Thai human rights worker who spoke to Alqunun said she told him she had been held in her room by her family for six months because she had cut her hair.
She was denied entry into the country by Thai immigration officials, who deny accusations that she was detained at the behest of the Saudi government.
Rahaf Mohammed Mutlaq Alqunun, 18, claims she was abducted on Sunday and had her passport confiscated by Saudi Arabian diplomatic staff on arrival at Bangkok's Suvarnabhumi airport.
Alqunun told Human Rights Watch that she arrived at Suvarnabhumi Airport in Bangkok Saturday evening from Kuwait, but that a diplomat from the Saudi Embassy in Bangkok seized her passport to prevent her travelling to Australia.
Thai immigration chief Surachate Hakparn said that Qunun was now "waiting for boarding, our immigration officer and Saudi Arabian embassy officials are with her". I can't even ask for protection or asylum in Thailand.More news: Golden Globes Hosts Call Out Hollywood Sexism
A Saudi woman being held at Bangkok airport is to be sent back, Thai authorities said Monday, after she made a desperate plea for asylum, saying she feared for her life after escaping an abusive family. "I'm shouting out for help of humanity".
Robertson said Alqunun was in transit to Australia when she was detained and did not need a visa, which is available on arrival anyway.
Qunun told Reuters she fled Kuwait while her family was visiting the Gulf country and had planned to travel from Thailand to Australia to seek asylum.
'Thai authorities should immediately halt any deportation, and either allow her to continue her travel to Australia or permit her to remain in Thailand to seek protection as a refugee, ' said Michael Page, deputy Middle East director at Human Rights Watch.
The Saudi embassy in Thailand and officials in Riyadh could not be reached for comment. "He came back with what seemed to be airport security and said that my parents objected and said I must return to Saudi Arabia via Kuwait Airways", she told Reuters news agency.
He also questioned a statement by Thailand's Immigration chief to the BBC that Ms Alqunun did not have a travel visa, which prevented her from entering Thailand.
In 2017, Dina Lasloom triggered a firestorm online when she was stopped en-route to Australia where she planned to seek asylum.More news: Global stocks soar on dovish Fed, strong US jobs data
The case follows the major worldwide backlash against the Saudi regime over the murder of journalist Jamal Khashoggi in Turkey.