The Peeping [Tou kui wu zui (2002) ]

From Imdb: This movie is inspired by the real-life scandal of Chu Mei-Feng, a Taiwanese politician and former member of the parliament who found her sex life bootlegged onto VCD and sold for pennies. Private detective Calvin is hired to tape the sex life of a female politician Kwai Fung Ming, but falls for her instead. He decides to help her counter-attack Law Sau Nam, who is the mastermind to discredit Kwai. Unexpectedly, Law is only one of the tools in this war. Written by Anonymous Daniel Wu stars in this noirish suspense thriller as Calvin, a private investigator hired to record a prominent politician's sex life. But he gets more than he bargained for when the politician, Kwai Fung Ming, turns out to be an incredibly beautiful young woman to whom he's immediately attracted. Soon, he's engaged in a passionate affair with Kwai and agrees to become a double agent to help Kwai shake down the man who wanted the goods on her. Written by Anonymous This film felt more like it was shot in the late eighties - only the cell phones and small camcorders through off the vibe. Lot's of blue Hong Kong lighting and smoke. The character of Calvin is likable and the eroticism is mostly shot through the anonymous hidden camera. - Kurt Weller