China's Jinjiang Group is in the spotlight after Brazil's labour authorities said workers at a factory it is building for electric vehicle maker BYD were victims of human trafficking working in "slavery-like conditions".

Brazilian labor authorities have accused Chinese electric vehicle company BYD and its contractor, Jinjiang Group, of human trafficking at a construction site in Bahia. The allegations highlight challenges in China's investment model and its relations with Brazil as BYD seeks to expand globally.

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.