Authorities on Wednesday night raided two brothels in Prachin Buri's Khlong Rang district and rescued more than 30 underage Lao girls.
The raid was carried out by a team of 30 police officers acompanies by women and children's rights advocate Paveena Hongsakul.
The two child prostitution rings used two karaoke restaurants, located about 500 metres from a police station, as a front.
The child prostitutes are aged between 13 and 17.
They said their agents lured them into the brothels and they received no payment as the brothel owners told them that their parents had to repay them more than 80,000 baht as transportation costs and business expenses.
They said the brothels would not let them eat or drink until they eventually worked as prostitutes. The brothels would then allow them only one meal a day.
All the rescued teenagers were taken to Kred Trakarn rehabilitation centre by Mrs Paveena's foundation, as the DSI continue to investigate the brothel operators.
People can report child abuse or violation of women's rights to the police or the Paveena Hongsakul Foundation for Children and Women at 1134 hotline.