Children as young as five are increasingly “perpetrating sexual abuse” because of what they are seeing on social media, charities have warned.

Increasing numbers of primary school pupils are exhibiting “harmful sexual behaviour” as a result of the web - with others groomed in their bedrooms in live broadcasts, they said.

The charity Barnardo’s said children were increasingly becoming perpetrators as well as victims, touching others’ private parts, or forcing them to watch pornography.

Their evidence to MPs also highlights growing evidence of an explosion of “live grooming” - with parents oblivious that children were sharing explicit content from their bedrooms.

Experts said middle-class parents had no idea that their children were being coerced into stripping for strangers, in scenes which were live-streamed globally, and harvested by paedophilic websites.