Police are recording 85 child sex crimes every day after a dramatic spike in reports of abuse, new figures reveal.
A total of 31,238 allegations of sexual offences against children, including rape and assault, were made to forces in England and Wales in 2013/14, research by the NSPCC found.
This was an increase of more than a third compared to the previous year.
The majority of the victims were aged between 12 and 16 but more than one in four - 8,282 - were younger than 11, the charity said. Of those, 2,895 are estimated to be aged five or under, including 94 babies.
More than three quarters of the reported abuse cases were against girls (24,457). Britain's largest force, the Metropolitan Police, recorded the highest number of sex crimes against children, with 3,523.
The data, obtained through Freedom of Information requests, reveals a significant year-on-year increase in the number of sex offences against children.
In 2012-13, the same research showed that a total of 22,654 were recorded by 41 police forces. All 43 forces in England and Wales responded in the latest study.
The NSPCC said that until now the total had largely remained steady and the 38% rise was the biggest increase in six years of requesting the figures. Since 2008/09, the number has increased by almost 50%.
Peter Wanless, the charity's chief executive, said: "These figures are disturbing and clearly illustrate child sexual abuse is a continuing and widespread problem that needs urgent action.
"But we know this is still only a fraction of the true number of victims because some endure an agonising wait of many years before telling anyone – and others never reveal what has happened to them.
"It's time to throw down the gauntlet to government which has to ensure all sexual abuse victims get specialist treatment to help them recover. By the end of this current Parliament there should be no children living in the shadow of abuse."
The statistics are the latest in a slew of recent findings indicating a spike in the number of abuse cases being reported and follow a trend that started in the wake of the Jimmy Savile scandal in 2012.
Analysts have suggested that publicity surrounding high profile cases has increased awareness and in turn given more victims the courage to come forward. Improved recording methods by police has also been cited as a possible factor.
A wide-ranging independent inquiry, headed up by New Zealand Justice Lowell Goddard, has been established by the Home Secretary Theresa May to probe allegations of historical child sex abuse and a Westminster paedophile ring.
Last month it emerged that police are investigating more than 1,400 prominent men, including politicians, celebrities and those linked to institutions, for historic child sex abuse.
The NSPCC will publish its annual report, How Safe Are Our Children?, today.
A Government spokeswoman said:"Children must be protected from the systemic and appalling cases of abuse we have seen in Rotherham, Rochdale, Oxford and elsewhere.
"That is why the Prime Minister hosted a Downing Street summit earlier this year to launch a package of new measures to better protect victims and survivors, bring more offenders to justice and ensure that those who are charged with protecting our children are held properly accountable.
"We have given child sexual abuse the status of a national threat so that it is prioritised by every police force, will shortly launch a new child sexual abuse taskforce and centre of expertise to improve local responses and we have provided £7 million funding to organisations that support victims.
"It is encouraging that police figures show more victims are having the confidence to come forward and report these often ignored and under-reported crimes."
Last month the National Police Chiefs Council (NPCC) said they have seen an "unprecedented increase" in the number of reports of abuse in the wake of the Savile affair.
Chief Constable Simon Bailey, NPCC national lead for child protection, said: "My assessment of the scale of child abuse chimes with the figures released today by the NSPCC.
"The service now looks upon child abuse very differently and victims can expect a professional response.
"As a result many, many, more victims have found the confidence to report abuse, knowing they will be treated with sensitivity and respect, that we will listen to them and that we will take their allegations seriously.
"Increased reporting means we are dealing with unprecedented number of investigations, however, I do feel that this is the tip of the iceberg.
"We have to balance the right of victims of previous abuse to justice with protecting children and the vulnerable now.
"We are working hard with our partners in education, health services, local government and the excellent support organisations to deal with this challenge, in which we all have an essential role to play. We would all recognise there is more we have to do."
Karen Froggatt, of charity Victim Support, said: "Children and young people who make the brave decision to speak up about this horrific crime deserve the very best level of support across all agencies.
"Sexual abuse can have a devastating and long lasting impact on people's lives."