At least 80,000 people in the UK pose an online sexual threat to children online, the Home Secretary is to reveal today.
Sajid Javid will disclose the figure and describe his shock at discovering the scale of the danger posed by paedophiles on the internet.
In a flagship speech today, he will outline his ‘personal mission’ to tackle child abuse in all its forms.
Mr Javid is expected to say: "It was when I visited the National Crime Agency's Child Exploitation Online Protection Command that the full horror of the scale and evolving nature of child sexual abuse was really brought home to me.
"One officer I met, who had previously worked in counter-terrorism for over 20 years, told me how in all his years of working he's never been so shocked by the scale of the threat or the determination of the offenders as he is in his current job."
Mr Javid will describe his horror at discovering that the NCA estimates there are up to 80,000 people in the UK who ‘present some kind of sexual threat’ to children online.
Other new statistics reveal referrals of child abuse images to the NCA have surged by 700 per cent in the last five years.
Separate figures indicate that police forces in England and Wales recorded around 23 child sexual offences involving the internet every day in 2017/18 - up from a rate of around 15 a day in the previous 12 months.
A week-long crackdown on online child sex offenders saw 131 suspects arrested - including teachers, a children's entertainer and a former police officer.
More than 200 raids led to 164 children being safeguarded following the operation.
The scale of offending has prompted demands for internet giants to take more action to stop access to sexual abuse images and videos.
The National Police Chiefs' Council lead for child protection, Simon Bailey, said: "The police response to tackling child abuse online has been robust, but there is a growing need to pursue offenders who pose the most harm to children and are using sophisticated technology to evade detection.
"Technology plays a significant part in all online investigations and there is an expectation that technology companies acknowledge their social responsibility in preventing and designing out this type of offending from their platforms.
"Only by working collaboratively with technology companies and law enforcement partners will we be able to minimise the risk posed to children online by predatory offenders."
There have also been calls for offenders who download indecent images of children to get tougher sentences.
Last month, Solicitor General Robert Buckland said the use of the internet to download or share images of child abuse is ‘as insidious a crime as direct sexual assault’.
In his speech, Mr Javid is expected to commit to prioritising urgent work to crack down on online child sexual abuse.