Children as young as four and five have been arrested for committing sex offences, shocking police figures have revealed.
Statistics also show an 11-year-old boy was held over the rape of a 16-year-old boy between 2012 and 2017.
In 2015 another 11-year-old boy also raped a girl under 13.
A Freedom of Information request revealed last year there were seven instances of children committing sex crimes in Northamptonshire, up two from the previous year.
The youngest recorded offenders were aged just four and five, with both guilty of committing sexual assault on boys who were under 13.
Of 889 child sex offences recorded by Northamptonshire Police in 2016/17, seven offences were recorded against babies.
The number of child sex crimes in the county recorded in 2016/17 increased from 868 offences recorded the previous year – and included rape, sexual assault and grooming.
A total of 316 crimes were recorded against children aged ten and under, while 87 were committed against children aged four and under.
Nationally there were a record 64,667 child sex offences recorded by UK police in 2016/17, up 15 per cent on the previous year with an offence recorded on average every eight minutes.
One in ten of these offences were flagged as having an online element – a 59 per cent increase on the previous year.
The total number of sex offences committed against children is unknown, as more children may not have come forward out of fear or embarrassment.
The NSPCC is now calling for government to direct more resources to ensure high-quality training and support to frontline police officers to tackle child sex offences.
Chief executive Peter Wanless said: “This dramatic rise is extremely concerning and shows just how extensive child sexual abuse is.
“These abhorrent crimes can shatter a child’s life, leaving them to feel humiliated, depressed, or 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 to rebuild their lives.
“To help them tackle the issue going forward, we must ensure the police are equipped to work with other agencies and provide ongoing support and training to officers on the front line.”