About 50,000 cases of sexual abuse were recorded by police and local authorities in the two years to March 2014. Official figures vastly underestimate the true scale of child sexual abuse. The actual number of children abused in that period is thought to be as many as 450,000. [A new] report, by the Office of the Children's Commissioner (OCC), found that about 85% of sexually abused young people are not receiving help and treatment. The majority of victims remain unidentified because the services that should protect them, including police and social services, rely on children to speak out, says the report. Two-thirds of cases, both known and unknown to the authorities, are believed to be victims of abuse in the family. Anne Longfield, the children's commissioner for England, said: "In recent years the terrible experiences of sexual abuse that some children have suffered in institutions or at the hands of groups of perpetrators have come to light and preventing and tackling these been made a priority." It was time to "wake up", Longfield said, and urgently address the most common form of child sexual abuse - that which takes place within families or their trusted circle.