Workers first spotted Olivia six years ago. Staff at the Internet Watch Foundation (IWF) were horrified that she was being subjected to sexual abuse and the images posted online. She was three years old.

“She was a little girl with big green eyes and golden-brown hair. She was photographed and filmed in a domestic setting. Sadly, it may well have been her home and she was with someone she trusted,” one worker, part of a team of IWF internet content analysts, recalls. “Olivia was in the hands of someone who should have looked after her, nurtured her. He betrayed her trust and in the most hideous way possible."

The man almost certainly profited from his actions, she adds: “The suffering of children like Olivia is frequently a commercial crime." And In three out of five times she was being raped, or sexually tortured. Some of her images were found on commercial sites. This means that in these cases, the site operator was profiting from this child’s abuse.”

“Olivia should have been playing with toys enjoying an innocent childhood. Instead, she was subjected to appalling sexual abuse over a number of years.”

We know Olivia was three because she was rescued five years later, aged eight. Police found her in 2013. But even now, five years after she was found and a further five years since she was first abused, the images are still in circulation.

“We counted the number of times we saw Olivia’s image online during a three-month period. We saw her at least 347 times. On average, that’s five times each and every working day,” the worker, explained.

Grotesquely, the worker, who cannot be identified for security reasons, has seen Olivia grow up through appalling abusive images and videos. “She was repeatedly raped and sexually tortured. For us, anyone who subsequently shared or paid to view this heinous material contributed to Olivia’s torment.”

That torment continues even after the abuse has ended because knowing the images may still be ‘out there’ is a mental torture, she added. “Knowing an image of your suffering is being shared or sold online is hard enough. But for survivors, fearing that they could be identified, or even recognised as an adult is terrifying.”

The IWF’s annual report, Once Upon a Year, to be published on Thursday reveals that they agency found and blocked record amounts of child sexual abuse imagery last year – 105,000 images. But it is an almost endless task. “It is like whack-a-mole”, says chief executive Susie Hargreaves OBE “For 23 years we have been removing from the internet images and videos showing the sexual abuse of children,” Ms Hargreaves adds. “Despite us removing more and more images than ever before, and despite creating and using some of the world’s leading technology, it’s clear that this problem is far from being solved.”

The IWF digitally ‘fingerprints’ images of child abuse it finds online enabling them to be removed more readily from other sites and archives.

While only a tiny fraction of the 350,000 images it has so far listed and removed are hosted in the UK (0.04 per cent), there are estimated to be 100,000 people in the UK looking at or looking for such images at any one time.

As a result the foundation is calling for more action to tackle this demand by making people aware that there are real young people behind the images: Children such as Olivia.

“With this continued demand for images of child rape, it’s a constant battle,” says Ms Hargreaves. “That’s why we’re calling for all the partners to get together to run a long term, well-funded prevention campaign. Without this, the battle just can’t be won.”

“Whilst pursuing a prevent agenda, we owe it to children like Olivia to keep doing what we currently do well, because they need to know that someone is here removing their images and videos. Prevention and removal should be tackled together.”

She said young men aged 16-25 appear to be the most likely to stumble on child sexual abuse imagery on line, and may then form a ‘habit’.

“If they then meet people online who like the same stuff it then becomes normalised and gives them a reason to come back.”

IWF is now planning too work with other partners and the UK Government to ensure people understand this is unacceptable and criminal, and can destroy the lives of the children involved for years to come.

IT will also work with a partner agency in the Netherlands, where almost half the imagery found last year (47 per cent) was hosted.

The UK Government’s planned restrictions on legal pornography, requiring an age check, will not affect those who distribute images of children, but ministers have also said they intend to make the UK the safest place to be online.

Ms Hargreaves continued: “We see the Online Harms White Paper as a huge opportunity for us all to step up and have a greater impact for people who use the internet and for child victims of sexual abuse.”

The IWF is also urging members of the public to report any sightings of child abuse imagery online. This can be done anonymously - last year four out of five such reports to the agency were anonymous.

 - Olivia’s name has been changed