The labor prosecutors’ office in Bahia state said in a statement that they are seeking 257 million Brazilian reais ($50 million) in damages from BYD, China JinJiang Construction Brazil and Tecmonta Equipamentos Inteligentes.

The lawsuit stems from an investigation that led to the rescue last year of 220 Chinese workers from the construction site of BYD’s new factory in the city of Camaçari. Prosecutors said the workers were brought to Brazil under false pretenses and with visas that did not match their jobs.

“Working conditions were extremely degrading. Five settlements were kept by BYD, JinJiang and Tecmonta. Some workers slept on beds without mattresses and had their personal belongings alongside with their food,” the prosecutors’ office said. “There were few bathrooms, which were not gender-assigned. In one of the settlements, there was one toilet for 31 people, forcing workers to wake up at 4 a.m. for their personal hygiene before their work.”