Zhaoyin Feng

Women who are groped on trains in East Asia face the further threat of their assault being filmed and uploaded for sale online. In a year-long investigation, the BBC World Service's investigative unit, BBC Eye, has gone undercover to unmask the men cashing in on sexual violence.

Investigation into a highly sophisticated scam involving criminal gangs, modern-day slavery and victims around the world who have lost millions of dollars.

Women who are groped on trains in East Asia face the further threat of their assault being filmed and uploaded for sale online. In a year-long investigation, the BBC World Service's investigative unit, BBC Eye, has gone undercover to unmask the men cashing in on sexual violence.