BEIJING (Reuters) - A former personal assistant to an exiled Chinese-born billionaire, who has made claims of high-level Communist Party corruption, has filed a lawsuit in New York accusing him of raping her, court documents show. In the civil complaint lodged with the New York Supreme Court on Monday, the 28-year-old woman said she was  lured  by the businessman, Guo Wengui, to New York under the guise of a one-week business trip. Instead, she was held  captive  and ultimately subjected to  repeated acts of mental cruelty and sexual violence , the suit says. She is seeking $140 million in compensation. Guo, who lives in New York, denied the accusation, describing it as  fake . The complaint says the woman is a Chinese national who was employed by one of Guo s China-based companies. She was told upon arrival in New York that she would work as one of the real estate tycoon s personal assistants, the complaint, reviewed by Reuters, says. It said Guo, also known as Miles Kwok,  forcibly took away  the woman s passport, threatened her, monitored her internet usage and restricted access to her phone and laptop computer. The woman said she was subjected to verbal and physical abuse, which soon escalated to sexual assault, before she managed to escape to the Chinese embassy in London during a business trip with Guo. After her return to China, the woman provided a statement and evidence of her allegations to police in China, the lawsuit said, without detailing the evidence. The Associated Press reported late last month that Chinese police were investigating the woman s claims. Guo refuted the accusation.  Of course it s fake,  he told Reuters. He said the  robbers of the country  engineered the allegations to  divert my attention, spread rumors and smear my reputation.  Guo, who left China in 2014, has named senior Communist Party officials in a deluge of graft accusations via Twitter posts and video blogs, attracting a loyal online following. He has provided little evidence for his claims. China calls Guo a criminal suspect, and articles in state media have accused him of crimes including bribery, fraud and embezzlement. At China s request, Interpol issued a global  red notice  for Guo s repatriation in April. Guo lodged an application for political asylum in the United States last week. 