Google and Facebook ad networks

Google and Facebook put ads in child sex abuse discovery apps

The apps involved used to be available on Google's Play Store for Android devices, and directed users to WhatsApp groups containing the illegal content.

Facebook and Google said they have taken steps to address the problem.

But the NSPCC charity wants a new regulator to monitor their efforts.

"WhatsApp is not doing anywhere near enough to stop the spread of child sexual abuse images on its app," said Tony Stower, head of internet safety at the child protection campaign.