The Independent Police Complaints Comission (IPCC) has published a report highlighting failings in the working practices of the Southwark Sapphire Unit - a police department dedicated to investigating serious sexual violence.
It found that officers there wrote off allegations as "no crimes", so they could reduce the number of unsolved cases on their books and meet official crime detection targets.
Ronke Phillips reports.
More top news
Is your street among London's trendiest hotspots?
Some of the best stories from the past week on itv.com/london. Got a story? Email us at firstname.lastname@example.org
This is Gordon Hill. But you may know him by now as the Wealdstone Raider.