More than 24 women in China have since come forward with similar stories of being plied with alcohol and then pressured to have sex with, or were sexually assaulted by, the 30-year-old.
The latest accusation, however, means that Wu could face criminal charges and civil lawsuits in the United States as well.
The woman said she had gone to one of Wu's now-notorious drinking parties where her phone was confiscated. She claimed that small white pills were being passed around and that she had lost consciousness before being sexually assaulted.
After the incident, she said she was too afraid of being victim-shamed to speak up. She also felt she had no hard evidence and was worried about being accused of extortion.
The American law firm representing her urged other alleged victims to come forward, as Wu had been to Los Angeles many times in the past for promotional events.
Wu's troubles began in July, when 18-year-old Chinese student Du Meizhu accused him in an explosive Weibo expose of having sex with her while she was unconscious.
Even before his arrest, he had lost several lucrative deals over the scandal. In recent days, his social media accounts with millions of followers have disappeared.
Other male celebrities, such as Singaporean singer JJ Lin and Taiwanese star Will Pan, have also been caught up in the controversy, although they have strongly hit back at rumours linking them to Wu.
Earlier this week, Chinese actress-model Angelababy won a lawsuit against a netizen who had made up stories about her, including of her cheating on her husband, actor Huang Xiaoming, with Wu. - The Straits Times/Asia News Network