Rotherham abuse victim: 'Police lost my evidence'
28 August 2014 Last updated at 22:34 BST
The police watchdog, the IPCC, is writing to South Yorkshire Police warning that "evidence of failures" must be passed on, after a report found at least 1,400 children were subjected to appalling sexual exploitation in Rotherham between 1997 and 2013.
Emma, not her real name, went to speak to officers about how she was being raped from the age of 13 but she felt her evidence was not taken seriously and said DNA she gave them was lost.
She has been speaking to Sian Lloyd and showed her previously unseen footage of her police interview - when she was just 14.
Viewers in the UK can watch a full investigation into the child abuse scandal in Rotherham in a special Panorama on Monday 1 September. Stolen Childhoods - The Grooming Scandal will be shown on BBC One at 20:30 BST.