Peter Davies, head of the Child Exploitation and Online Protection Centre (CEOP), said there was now a "class of child abusers very proficient in technology" who are consistently trying to evade authorities by finding new means of accessing children.
Speaking to Daybreak, he said: "The old model, with a view of meeting online with a view to meeting offline and then physical abuse taking place is actually a diminishing, these days sexual abuse of children can take place purely online."
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Downpours keeping us on our toes today
The M20 in Kent has been closed in both directions after a pedestrian bridge allegedly collapsed on the motorway on Saturday.
The AA have warned of traffic jams and urged people to carry extra water in their vehicles because of the warm weather.