City's sex industry booms despite repeated crackdowns, report Qiu Quanlin in Dongguan, Cui Jia, Tang Yue and Yang Wanli in Beijing.

On a chilly Monday afternoon, Wang Dandan walked idly around the Yuanfeng Hotel in Zhongtang, a township in Dongguan, Guangdong province, where she worked for just one month at the end of last year.

The hotel door was sealed, with an official banner signaling that operations had been suspended. A security guard made his rounds.