An illustrative example of official involvement in organized crime can be found from 1920s and 1930s Shanghai, where Huang Jinrong was a police chief in the French concession, while simultaneously being a gang boss and co-operating with Du Yuesheng, the local gang ringleader. The relationship kept the flow of profits from the gang's gambling dens, prostitution, and protection rackets undisturbed.[citation needed]

When was Jinrong a police chief in this area?