HONG KONG — The Hong Kong police arrested 75 people in a raid of a local prostitution ring, the police said Thursday, a case that showed the breadth of the problem in the territory.

Although working as a prostitute is legal in Hong Kong, the semiautonomous Chinese territory bans organized prostitution, and a conviction for knowingly taking from a prostitute’s earnings could result in a 10-year prison sentence.

Among those arrested in the raid Wednesday night were eight Hong Kong residents charged with profiting from the earnings of sex workers, running a “vice establishment” and operating an unlicensed massage parlor.

The arrests highlighted how organized gangs, known as triads in Hong Kong, are believed to wield control over the local sex industry, which often relies on women from mainland China and other countries to fuel the trade. The women arrested in the raid came not only from mainland China but from Southeast Asia, Russia, Kazakhstan and Ukraine, The South China Morning Post reported, quoting police officials.