Chinese workers at a construction site in Brazil for a factory owned by China's electric vehicle producer BYD are victims of human trafficking, Brazilian labor authorities said on Thursday in a growing controversy in BYD's biggest overseas market.

BYD has been building the factory with an annual capacity of producing 150,000 cars initially in Brazil, the Chinese EV giant's largest overseas market, as part of plans to start production there.

"Slavery-like conditions", as defined by Brazilian law, include debt bondage and work that violates human dignity. The MPT added that the situation also constitutes "forced labour", as many workers had their wages withheld and faced excessive costs for terminating their contracts. BYD said affected workers had been moved to hotels.