'My daughter thought she was talking to a boy online and sent nude pics - but it was someone else'

Warning: This article addresses child sexual abuse that readers may find distressing Marie and Dan say their daughter's childhood stopped when she was just 12 years old.

"Her innocence was taken away," Dan says. Their child believed she was talking online to a 14-year-old boy from London.

In fact, she was being preyed on by a predator who she sent nude photographs of herself. A tearful Marie is haunted by the impact on her daughter.

"You go through all those questions thinking, 'I should have done more because I'm her mum, and I'm supposed to protect her'," she says. The couple describe how the offender told their daughter he knew where she lived, and threatened to harm her and her family if she failed to do as he asked.

"She was really fearful we were going to be hurt," Marie says. Dan adds: "Then, once that threat abated slightly, it was then, 'well, I'm going to commit suicide if you don't keep providing me with images'." Experts say there is a "notable gap" in what we know about how offenders are using online platforms to exploit children - and they want to address it.

Sky News has been given exclusive access to a world-first report surveying online perpetrators globally. Researchers carried out an anonymous survey among perpetrators who have used known keyword terms to search for child sexual abuse material on the dark web.

More than 20,000 responses were received, with participants taking part voluntarily, in several different languages, and they did not receive payment. 'Way too easy to access child abuse material' It found that most offenders (59%) who search for child sexual abuse material first saw it when they were children themselves - including some (13%) when they were 10 or younger.

The research by Protect Children, funded by Ofcom, also found around a quarter (24%) of offenders first encountered child sexual abuse material by accident, without searching for it. One offender described it as being "way too easy" to access child abuse material.

Another said: "It used to be nearly impossible, now it's two clicks away, well, maybe three." Other perpetrators said "it's all over the normal web.