Thousands of children, including a boy aged five, have been investigated for sexting, the BBC has learned.
Nearly 400 children under the age of 12 have been spoken to by police in the last three years in England and Wales.
Figures obtained by the BBC show more than 4,000 cases since 2013 where children have taken explicit pictures of themselves and sent them to others.
It is illegal to possess, take or distribute sexual images of someone who is under 18, including of yourself.
The five-year-old, from County Durham, was spoken to by officers of Durham Constabulary last year.
He is the the youngest person to be investigated for sexting by police forces in England and Wales who responded to a BBC Newcastle request for information.
The force's DCI Steve Thubron said sexting issues were dealt with on a case by case basis, with a focus on safeguarding children.
He said incidents were recorded in line with national crime recording standards:
"We deal with incidents proportionately and obviously do not criminalise children. We have worked with other agencies to provide advice and guidance to both schoolteachers and young people. We would urge any children who are worried to speak with a trusted adult or call 101."
The most common age of those involved in sexting is 13 or 14.
A 10-year-old boy - only just at the age of criminal responsibility - has been cautioned by Northumbria Police for sexting.
The boy sent a sexual image of himself to an 11-year-old child using Oovoo - a free social media video and image sharing app.
- Children can talk to a ChildLine counsellor 24 hours a day on 0800 11 11 or in an online chat.
- Parents or carers concerned their child is being contacted by adults as a result of having shared sexual imagery should report it to the NCA or Ceop.
- Parents and carers can contact the NSPCC Helpline on 0808 800 5000; email email@example.com; text 88858; or call the Online Safety Helpline on 0808 800 5002.