Sixty-six migrant workers from military-ruled Myanmar were kept like slaves in a Thai seafood factory for up to seven years, official media alleged on Thursday in a rare admission that thousands of its citizens work abroad.
In the past, army-controlled newspapers in the former Burma denounced those who left the country to work as "unpatriotic traitors".
"They were held captive in water tanks, underground apartments, ceilings of rooms and partitioned rooms so they could not get in touch with the outside world," the papers, all of them mouthpieces of the military government, alleged.
"They had to work hard for 18 hours every day but were paid no wages until they were rescued," they said.
The workers, held for between six months and seven years, were freed in September from a seafood factory called Maha Chai west of Bangkok by the Human Trafficking Multidisciplinary Organisation of Thailand, they added.
The International Labour Organisation (ILO) in Bangkok confirmed the incident, which it described as "one of the more extraordinary cases of migrant worker exploitation".
The Thai government had filed criminal charges against the factory's operators, although the case has yet to be completed, the ILO said.
The reports - the first time regime-controlled media have shone light on the plight of migrant workers - said that of 300,000 Myanmar citizens working in Thailand, only 80,000 were legal.
Rights groups think the real total could be as high as two million.
The newspapers said the government had granted licences for 70 overseas job agencies and would start issuing temporary passports in November to former illegal workers to allow them to apply for proper migrant worker passes.
