Children as young as five have been excluded from school for sexual misconduct ranging from abuse, harassment and bullying to 'sexting' inappropriate images of themselves and watching pornography.
The range of sexual misconduct in schools also included inappropriate touching, lewd behaviour and sexual graffiti, with some children being disciplined within their first year at school - when they are aged between four and five.
Though some of the children involved were reception age pupils, 13, 14 and 15-year-olds were the most likely to be sanctioned.
Local authorities were cautious about releasing any specific details of the reported incidents to the Press Association, who carried out the investigation, but figures revealed that the number of boys involved in sexual misconduct outnumbers girls by a rate of around 10-1.
In the Merseyside borough of Knowsley, a five-year-old boy was excluded for using sexually explicit language, while another five-year-old was given a similar punishment for "inappropriate touching".
Cambridgeshire's Sexual Behaviour Service reported a range of incidents including watching pornography, sending indecent images of themselves and 'inappropriate sexual thoughts".
Brent Council reported 159 incidents, including three boys, aged between eight and nine, permanently excluded in 2011 for sexual misconduct. The same authority also disclosed one 12-year-old boy was excluded for 30 days for his sexual offending.
A small number of incidents involving members of staff were also reported. In Lincolnshire, there was a substantiated allegation that an inappropriate image of a three-year-old girl was taken by a member of staff.
The records obtained by the Press Association showed there were more than 2,000 reported incidents between January 2010 and September 2013. A number of the 153 authorities contacted did not hold the information centrally or refused to disclose it meaning the true figure could be higher.
Six children in reception classes across England were involved in a sexual act in a school, the figures showed. There were a further 15 incidents involving six and seven-year-olds, rising to 69 incidents for children in Year Six (age 11) at the time of the sexual misconduct.
There was a surge in incidents as children reached secondary school - with 175 incidents in Year 7. The figures show further increases in the next three year groups - with 248 incidents for 13-year-olds, 256 for those a year older, and 240 for those in Year 10 (age 15).
Politicians, child welfare charities and activists today reacted to the startling details of the investigation describing them as 'extremely concerning' and calling on the government to take action.
Jon Brown, head of tackling child sexual abuse at the NSPCC, said: "The extent of sexual harassment, inappropriate sexual behaviour and in the worst cases violence by children is extremely concerning.
"Exposure to extreme, sometimes sexually violent and degrading material is now only a few clicks away and this can warp young people's views of what is normal and acceptable sexual behaviour. Sexting (sending sexual text messages) is now the norm for many young people who may find once they start sending explicit pictures of themselves the situation spirals out of control.
"We need good quality, age appropriate education in schools to help young people develop healthy, positive relationships with each other, so that children understand consent, do not feel so pressurised to behave in a sexualised way, and respect themselves and others."
A Department for Education spokesman said: "We share headteachers' serious concerns over sexual misconduct by pupils. That is why we have given teachers the power to search for and delete inappropriate images from phones, while the Child Exploitation and Online Protection Agency and the Sex Education Forum have produced useful material to help schools deal with 'sexting'.
"Schools should teach pupils about respect for others and how the law applies to sexual relationships. And our statutory guidance is crystal clear - if a professional thinks a child is at risk of harm they should report it immediately to social care.
"It is encouraging that official statistics show exclusions for sexual misconduct are decreasing year on year and represent less than 0.05 per cent of exclusions across the country."
The figures on sexual misconduct in schools
The Press Association asked 153 local authorities in England for details of every incident of a child being involved in a sexual act in a school, recorded as a separate item, between January 2010 and September 2013. They show:
Isle of Wight 15
Milton Keynes 3
NE Lincolnshire 12
N Lincolnshire 51
N Somerset 6
N Yorkshire 124*
S Tyneside 37
* Denotes minimum number of incidents.