Social worker Estelle Thain told ITV News that she became increasingly concerned about one of the Peterborough victims when she became "too frightened" to speak about her experiences.
"It got to the point where we had to place her in foster care to move her away from Peterborough," she said, "which was where she was putting herself at risk."
"She had been moved a couple of months to foster placement, which was a long way from Peterborough, before she got to a point where she got comfortable to disclose some of the things that had been happening to her."
"She was 12 or 13 at the time," she added.
More top news
Storm Imogen will cause problems across much of the south today, but it will be calmer in the north.
David Cameron is expected to warn that voting for a "Brexit" would result in refugee camps springing up across the south-east of England.
Beyonce, Coldplay and Bruno Mars performed a medley of their hits during a powerful half-time performance at Super Bowl 50.