青幫
The city was also the center of national and international opium smuggling during the 1920s. In the 1930s, "The Great World" amusement palace was a place where opium, prostitution and gambling came together under the leadership of gangster Huang Jinrong also known as "Pockmarked Huang". Huang was the highest-ranked Chinese detective in the French Concession Police (FCP) and employed Green Gang ("Qing Bang") leader Du Yuesheng as his gambling and opium enforcer. The Green Gang became a major influence in the Shanghai International Settlement, with the Commissioner of the Shanghai Municipal Police reporting that corruption associated with the trade had affected a large proportion of his force. An extensive crackdown in 1925 simply displaced the focus of the trade to the neighboring French Concession.