Derbyshire police received almost 730 reports of sex crimes against children under the age of 18 last year, shock figures show.
Of those, more than 80 of the boys and girls were aged just five and under.
The figure of 727 – two a day – is 42 per cent higher than the previous year when the number of reports was 510.
The statistics have come from a Freedom of Information request made by the NSPCC to police.
An NSPCC spokesman said: “While shocking, these figures may only reveal a small part of the whole picture as many children are afraid to speak up.”
Peter Wanless, the charity’s chief executive, said: “Sexual abuse can shatter a child’s mental health.
“It can leave them anxious, depressed and even suicidal.
“That is why it is crucial every single child who has endured abuse and needs support must get timely, thorough help so they can learn how to handle disturbing emotions and behaviours and rebuild their lives.”
Sandra McNair, the NSPCC’s Midlands head of service, added: “It is unclear why there has been such a staggering increase in recorded offences but there are a variety of possibilities to explain the figures.
“Victims may now feel more confident in coming forward following greater awareness about sexual abuse.
“Police forces may have improved their recording methods or become more vigilant about sexual crimes.
“Following high-profile cases about historical sex abuse, more survivors might feel encouraged to come forward.”
Nationally, a total of 45,456 child sexual offences were recorded last year, an average of 124 a day.
Report child sex offences to police on 101 or Crimestoppers on 0800 555 111. If you are worried about a child, call the NSPCC on 0808 800 5000 or email email@example.com