Brazilian authorities say they have rescued more than 160 laborers working in "slavery-like" conditions at a construction site for a factory of Chinese electric vehicle maker BYD in northeastern Brazil.

The plant was being built in the state of Bahia with a production capacity of 150,000 cars per year when completed.

An investigative team from the Brazilian government on Monday announced the rescue of 163 workers. Local media say they are Chinese nationals hired by a contractor of the construction ordered by BYD.

Footage released by the investigative team of the workers' dormitory shows beds without mattresses only covered with sheets, indicating they were working in poor conditions.

The company said it will terminate the contract with the construction firm, and promised to comply with Brazilian laws on the protection of workers' rights.

A spokesperson for China's foreign ministry told a news conference on Wednesday that the Chinese embassy and consulates general in Brazil are maintaining communication with the Brazilian side to verify the situation and to handle the issue properly.

She added the Chinese government attaches great importance to the legitimate rights and interests of workers, and asks Chinese-invested companies to do business in accordance with laws and regulations.