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.

Announcement came days after labour authorities also said they found Chinese workers at factory in Bahia were victims of human trafficking.

A spokesperson for Chinese automaker BYD has objected to reports about poor conditions at a construction site in Brazil where it is building a factory, saying the allegations were aimed at “smearing” China and Chinese brands.