Hundreds of British children are being blackmailed into performing sex acts online by paedophiles who threaten to send obscene images of the victim to their family and friends.
Investigators from the Child Exploitation and Online Protection (Ceop) centre said children as young as eight have been targeted and are being driven to self-harm and suicide by their abusers.
In the past two years across 12 investigations, 424 children worldwide have been blackmailed in this way, of whom 184 were from the UK, Ceop said.
ITV News correspondent Paul Davies reports:
Internationally, seven committed suicide, including 17-year-old Daniel Perry from Dunfermline in Fife, who died on July 15 after being tricked into thinking he was talking to an American girl online.
Another seven seriously self-harmed, of whom six were from the UK, Ceop said.
Experts believe thousands of British children could have been targeted by abusers intending to trap victims.
Ceop said paedophiles create fake online personas to pose as children, even geographically researching the areas where they wish to target victims, and persuade them to share sexual images or perform sex acts on camera.
Ceop deputy chief executive Andy Baker told ITV News the internet "amplifies" the opportunities of paedophiles for abuse."
Mr Baker said, "They send out hundreds if not thousands of emails to children they spotted on social networking sites - they've seen their profile, they research them, and they also contact them as if they know them."
Mr Baker said the paedophiles then "dupe" the children into believing that they are around the same age and "pretty quickly" ask to see explicit pictures of them.
"Once you pass over that photograph that's it - that's the start of this real sexual extortion and demand, and then the fear kicks in," he added.
The centre said blackmail can be reported to the NSPCC helpline on 0800 328 0904, or to police.
If you are in distress and need some support, the Samaritans are available 24 hours a day on 08457 90 90 90 or click here for their website. For those in the Republic of Ireland, call 1850 60 90 90.