A rapist aged four-years-old is among almost 800 children investigated for sex crimes

UK: Growing numbers of children, some barely out of nursery, are being quizzed by police over sex attacks on other youngsters.

Shock official figures obtained by the Sunday Mirror show nearly 800 under 10s have carried out sex crimes against other children since 2009.

One aged just four was investigated by police last year for rape.

The chilling statistics give a terrifying insight into the child abuse crisis facing Britain today – and the growing menace of online porn.

Our findings also show that the annual toll of mini sex offenders has DOUBLED in the last three years.

The sickening cases include: a three-year-old boy who sexually assaulted another youngster in Lancashire. A five-year-old lad found to have raped a boy in Lincolnshire. And a nine-year-old girl from Manchester who took indecent ­photographs of other children.

None of the children responsible for the acts could be prosecuted because they were under the age of 10 – the age of criminal responsibilty.

Rape by children at such a young age constitutes penetration of their victim other than sexual intercourse.

Child protection experts said many of the young perpetrators will have been abuse victims themselves – but that growing easy access to online pornography is also to blame.

The figures make a mockery of David Cameron’s vow two years ago to ensure pornography is blocked by internet providers on demand from the householder.

NSPCC spokesman Jon Brown said: “These figures may seem hard to believe but, unfortunately, there are cases of children as young as three committing sexual offences.

“These children may well have ­experienced very severe trauma and abuse themselves. That kind of ­behaviour won’t just have come out of nowhere.

"They will undoubtedly have been victims of sexual abuse. It’s terrible. There should be no cases like this. These children are not child paedophiles – they are victims themselves.”

The alarming rise in child-on-child abuse was revealed following a

Freedom of Information request by the Sunday Mirror to all police forces in England and Wales.

Thirty-three replies revealed 776 ­children under the age of 10 carried out sex crimes in the last six years. But that figure is likely to be much higher because 10 forces did not respond.

In just three years, the number of children under 10 committing sex offences has doubled, from 128 in 2012 to 254 last year.

Cases include a four-year-old ­questioned over a rape in London last year. Scotland Yard refused to disclose if the child was a boy or girl.

Officers from Greater Manchester Police dealt with 18 horrific cases of children under 10 raping other children between 2009 and 2014.

The offenders included a boy aged six, five boys aged seven, seven boys aged eight and five boys aged nine.

Dozens more children under 10 were found to have committed sexual assaults in Greater Manchester, including a seven-year-old girl who sexually assaulted a boy.

A nine-year-old girl was investigated by the force for taking or making ­indecent photos of other children.

Det Chief Insp Colin Larkin, of the force’s Public ­Protection Division, said: “If we have cases where children under the age of 10 are believed to be suspects in a criminal offence they are treated ­sensitively, by specially-trained officers.

“This will always involve multi-agency safeguarding measures in place. We work closely with partners including education, health and children’s services as well as Barnardo’s and the NSPCC.”

Meanwhile Thames Valley Police investigated two separate incidents involving a five-year-old girl and four-year-old boy who committed unlawful sexual activity with other children.

Other cases included a seven-year-old boy who raped a girl aged under 16 and a nine-year-old boy who raped a boy under 13.

A total of 64 children under 10 have been investigated in the Thames Valley area for sex offences since 2009.

The litany of sickening cases across the country also include a boy from south west Wales who committed voyeurism offences at the age of eight and a five-year-old boy from Lancashire who sexually assaulted a girl under 13.

An expert from a charity tackling child sexual abuse described our findings as “tragic”.

Donald Findlater, research director at the Lucy Faithfull ­Foundation, warned the statistics were probably the tip of the iceberg because many ­incidents are never reported.