The Criminal Court has acquitted Montha "Ying Kai" Yokrattanakan of one of the human trafficking charges against her, in which she allegedly exploited a minor - a girl who served as her maid six years ago.
The girl, whose name was withheld, decided to accompany Montha from her home province of Mae Hong Son to Bangkok in 2008 after the woman, who claimed she liked helping poor people, promised to give her work and support her studies.
Montha was later accused of having deceived the 16-year-old and treating her badly.
The court on Friday found there was no evidence that Montha had forced the girl to work from 5am to 10pm, paid no wages and illegally detained her, as charged, Matichon Online reported.
The girl and other maids were allowed to leave the house and meet relatives, and there was no clear evidence of forced employment, the ruling said. Both the girl and her parents had been aware of her trip to the capital from the beginning.
The girl had worked with Montha until late 2010, when she ran away.
Prosecutors accused Montha of threatening to file a complaint of theft against the girl if she did not return. The court also found this accusation had no grounds.
Although Montha paid the girl only 1,000 to 3,000 baht a month, which was less than she had promised and below the rate set by the labour law, the court could not issue a compensation order because Montha was not found guilty in this case.
Filing of false theft charges and mistreatment are among the accusations made by Montha's former maids, which led prosecutors to charge her with several counts of human trafficking.
On Oct 19, the Criminal Court sentenced Montha to three years in prison for a human trade-related case and ordered her to pay 590,007 baht compensation to a female victim forced to work as her maid.
Her initial four-year jail term was commuted to three because she had cooperated.
Earlier on June 6, the court sentenced Montha to seven years in prison, reduced from an initial 15, after she confessed to violating Section 112, the lese majeste law.
Montha claimed she was a khunying, a title bestowed only by His Majesty, and used it for her own gain, an action that reflected badly on the monarchy.