Foshan police bureau, in Guangdong province, has set up a special team to investigate crime related to the environment.
The so-called environmental protection police follow the example of Hebei province, which set up a similar unit in September last year.
Since then, environmental protection police have appeared in Hubei, Liaoning, Anhui and Guangdong provinces.
The country has devoted more efforts to crackdown on environmental crime since last year.
In the second half of last year, police handled 247 criminal cases related to environmental pollution, the the total number of similar criminal cases in the previous 10 years, according to Beijing News.
Most cases handled by the environmental protection police involve the discharge of more than 3 tons of heavy metals and dangerous waste materials.
Enterprises that discharged pollutants used to ignore investigators from the local environmental protection bureau. With environmental protection police teaming up with investigators from the bureau, enterprises are more co-operative, said Zhu Yuguang, deputy chief of the Baoding environmental protection bureau in Hebei.