as young as eight are being blackmailed into performing sexual acts on webcams by abusers in increasing numbers, research by the Child Exploitation and Online Protection centre shows.
In a report published on Friday Ceop says it has uncovered a number of children self harming or, in one case, killing themself as a result.
The trend for online blackmail to cause children to harm themselves is a small one but its growth is worrying experts who investigate child sexual exploitation.
In the past two years Ceop has investigated 12 cases where children were blackmailed into performing sexual acts on a webcam.
In the past two years, according to figures from police forces in the UK and abroad, 424 children have been a victim of online sexual blackmail in some form – 184 in the UK.
Ceop says research shows that of those victims seven children seriously harmed themselves as a result – including six from the UK, one of whom killed themself.
Often the offenders – who frequently pose as a child online at first – go on to threaten to share naked pictures of the victim with friends and family unless they do what they are told.
In one case that Ceop investigated the offender collated images he had obtained by blackmailing a child into a file entitled "Slaves".
Andy Baker, deputy chief executive of Ceop, said: "These offenders are cowards. They hide behind a screen, and in many cases make hollow threats which they know they will never act on because by sharing these images it will only bring the police closer to them.
"Our research shows that the power offenders use on their victims means children who are forced into performing acts on webcam or sending pictures feel trapped, and some tragically go on to self harm or in the worst cases to take their own lives."
The NSPCC has set up a 24-hour helpline for children or adults worried about such blackmail (0800-328 0904).
Forty-six forces were asked to provide details of cases where a child in the past 12 months had been coerced into producing sexual images, then threatened with them being distributed and whether the victim had self harmed as a result.
One teenager who was interviewed by police in a blackmail case told investigators she was targeted when she was 12.
"This person started talking to me in the internet
and said he was around my age," she said.
"Then the conversation sort of developed into other things. He'd steer the conversation in a way that was turning a bit dirty then he'd start asking for other types of pictures as well.
"If you try and say: 'Oh I don't want to talk about that,' he'd threaten or blackmail me, saying he'd send my dad all the chat logs if I didn't do what he said ... he started to do that every week.
"He always used to say: 'You know what happens if you don't send me any.' "
Investigators first uncovered online blackmail for abuse in 2010 in an investigation codenamed Hattie. It led in 2012 to the jailing of two Kuwaiti brothers. They had targeted 110 children, including 78 in the UK, and forced them into performing sex acts online.
Researchers say children are more vulnerable to such grooming if they are isolated or suffering problems at school or home. Parental monitoring of online use by young people is one of the key ways to prevent children being targeted. But more than two thirds of parents do not have filters on their children's smartphones.
Abusers often use instant messaging on smartphones to contact victims – it was used in a third of cases in the last year. The rise of smartphone ownership amongst 12-15 year olds also increases the risks.
Letzgo Hunting, a controversial vigilante group targeting potential child abusers, announced on Thursday night that it was abandoning its operations.
The move follows the suicide of Gary Cleary, whom the group had accused of grooming a child over the internet, and criticism by police that its tactics could disrupt their own operations.
The members of the Leicestershire-based group posed online as girls aged 12 to 15 and interacted with men who they believed posed a risk to children before arranging real-life meetings in car parks, filminged the confrontations and passing the evidence to police.
Cleary killed himself in May, days after he was arrested and released on police bail after a Letzgo Hunting sting. An inquest into his death was held last week.
In a statement on its website the group said: "Letzgo Hunting is done with, we always did what we could with the best intentions of children in mind, and sometimes we may have been a little over-passionate, but this is because we believe children should be protected.
"But now its over to you guys, we have shown you how easily these people groom children online, its your turn to protect them now, Letzgo Hunting have as of 17:00 on 19/09/2013 suspended all hunting activities with no view to continue them."
Predator and prey
From a case investigated by CEOP, this is an online chat between a perpetrator – an adult male pretending to be a teenage boy - and a 16-year-old girl
Offender Hi, asl? [age sex location]
Victim 16 female You?
Offender 17 m
Victim Ccool ;)
Offender Wuu2 x
Victim Fck all u? X
Offender Same babe
Have u cam Or u like shy :/ x
Victim I have cam but can only do video call && i look a mess today x
Offender Haha then sex it up babee ;P
Just go on :) x
Victim Hmmm do II have to x
Offender Yeh ;P
I make u do stuff on cam that befor a month ago right
Offender And u do 4 times right
Offender So i want u again for 2 times again and I ll delete u from my msn
Victim Im not doing anything dirty...u sed that i didnt have to
Offender I know but u have no choice only u listen to me this time ok
2 times more and u be free forever
Victim Omg u promised Yeahhh thanks for making me want to cry
Uve got ur slaves ...you sed that you didnt need me no more Thanks for making me want to kill myself
Offender Ok that all 2 times more Then u be free forever Send cam now
Victim No i really don't want to...please don't make me
Offender Send cam
If u keep saying no ill let u do 4 times
So u agreed 2 times then u cant see me anymore
And if u agreed ill ask u when u start do it ok
Victim What have i done wrong to you for you to treat me like this :(
Offender Realy nothing
But ur hot that why i like u do stuff for me
And u will do it 2 times more
Brb 2 mins
Victim Well u promised ii wouldnt have to do it
I HATE MY LIFE!
Oh ok...i feel sick
Offender Remember i have ur video so don't do anything bad
See u later