The factory was scheduled to be operational by March 2025, and was to be BYD’s first EV plant outside of Asia.
Workers hired by Jinjiang Construction Brazil lived in four facilities in the city of Kamari.
At one such facility, workers were made to sleep on beds without mattresses, according to prosecutors.
Each bathroom was also shared among the 31 workers, forcing them to get up very early to get ready for work.
“The conditions in the residences presented a worrying picture of precariousness and degradation,” the MPT said.
“Slavery-like conditions,” as defined by Brazilian law, include debt slavery and work that violates human dignity.
The MPT added that the situation also constituted “forced labour”, as many workers had their wages withheld and faced excessive costs to terminate their contracts.
BYD said the affected workers have been shifted to hotels.
It added that it had conducted a “detailed review” of the working and living conditions of subcontracted employees, and had asked the construction firm to make improvements “on several occasions”.
BYD, short for Build Your Dreams, is one of the world’s largest EV manufacturers.
It has sold more electric vehicles than Elon Musk’s Tesla. In the last three months of 2023, as both were fighting for the top position in the sector.
The company is also making inroads in Brazil, its largest overseas market by a wide margin.
It first opened a factory in São Paulo in 2015, producing chassis for electric buses.
Last year, it announced it would invest 3 billion reais ($484.2m) to build an EV manufacturing plant in Brazil.
EV sales in China have increased due to government subsidies. which encourages consumers to trade in gasoline-powered cars for EVs or hybrids.
But there is a growing backlash overseas against what some see as the Chinese government’s unfair support for domestic automakers.
Major markets such as the US and EU have imposed tariffs on EVs from China, with more tariffs expected under the incoming administration of US President-elect Donald Trump.