Police say around 100 women in Japan who thought they were participating in a sleep study were actually drugged and raped, their attacks recorded and sold to porn sites.
Authorities arrested 54-year-old Hideyuki Noguchi, after one of the women saw herself in a video.
Police investigated and arrested Noguchi, who now faces charges of incapacitated rape in almost 40 cases.
Authorities say Noguchi has told them the number of victims is about 100.
The assaults allegedly began in 2012 when police say Noguchi took out an ad seeking participants for a sleep study. The ad sought women from their teens through their 40s.
But authorities say Noguchi has no medical training and the study was merely a ruse to isolate women, drug them, assault them and film the attacks.
Police say Noguchi sold the videos to porn sites, making around $100,000.
– By: Emma Lacey-Bordeaux and Will Ripley. Journalist Chie Kobayashi contributed to this report.
