The daughters of Thaksin Shinawatra have lashed out at the online leak of details of their first-class flight to London with eight suitcases.
But Pintongta and Paetongtarn Shinawatra denied they were following in their father's footsteps and fleeing the country.
Thai Airways International, meanwhile, says it's investigating whether one of its employees committed the ethical breach of leaking passenger information.
The screen shot of the sisters' flight details, apparently taken with a mobile phone camera, has gone viral on social media. THAI said it did not want to jump to conclusions about staff involvement as the picture could have been taken by someone else.
The flight information of Paetongtarn and Pintongta Shinawatra, apparently captured on a mobile phone camera, has gone viral in social media.
The picture of the computer check-in monitor shows the names, seats and ample baggage allowance of Pintongta, 31, and Paetongtarn, 27. It was posted late Thursday, shortly after their flight left Bangkok.
By Friday, the image was causing a sensation on local web forums, with some commentators criticising the ethics of posting private flight details and others questioning if the Shinawatra sisters were fleeing the political heat at home.
Both sisters posted messages on Friday saying they were in London and would return soon.
"[I'm'] not seeking asylum," Miss Paetongtarn said on Instagram. "[I'm] here for six days to work.
"Haters will always make up stories to accuse us."
A THAI official said the pair had checked more than 150 kilogrammes of baggage and were seated in first class. He spoke on condition of anonymity, citing the airline's policy of not disclosing passenger information.
Older sister Pintongta posted a picture of herself strolling along a sidewalk in a Chanel scarf and carrying a Hermes Birkin bag.
"I'm here with my sister to work and will be back within a week," Miss Pintongta said. "I guess there will be no more stories for the protesters to talk about? Give yourselves a break."
The flap over the sisters' trip comes at the end of a turbulent week in local politics. Massive street protests have been held against an amnesty bill, now killed by the Senate, that would have allowed Thaksin to return home.
Thaksin was overthrown by a coup in 2006 and fled the country in 2008 to escape a corruption conviction that he says was trumped up by the military-backed government.
THAI, meanwhile, sought to deflect criticism of a possible ethical violation.
"It could be that somebody else accessed the information. It might not be one of our employees," spokeswoman Theerasin Saengrungsri said. "We have to look into this."
It wouldn't be the first time that anti-Thaksin airline employees have broken the rules.
A Thai flight attendant working for Cathay Pacific lost her job last December after posting a picture on Facebook of Paetongtarn Shinawatra's seat number and writing that she wanted to throw coffee in her face.