BYD Co. reiterated its commitment to commence production of electric vehicles in Brazil this year, despite authorities accusing one of the Chinese carmaker’s subcontractors of labor abuses.

China’s labour practices are driving a wedge between the world’s biggest EV maker and efforts to expand globally in areas where employee protections are paramount.

Hyundai and Kia dominate their home market of South Korea, but Chinese automaker BYD could prove to be a true threat to their ...