Young girls filming themselves on mobile phones has fuelled the record number of child abuse websites discovered and taken down by a UK watchdog last year.

The Internet Watch Foundation (IWF) said it has seen an “astronomical” rise in videos and images appearing on paedophile websites that girls as young as 11 had been groomed into making of themselves.

The charity, which scours the open internet for abuse material, said self-generated images now made up a third of the material it found on the 132,700 websites it removed in 2019 - a rise of more than a quarter (26 percent) on 2018.

It comes as the IWF called for internet companies to have a legal requirement imposed on them to scan for known child abuse material.

Susie Hargreaves OBE, CEO of the IWF, said the girls in the self-generated material often appeared to believe they were communicating with another child.

She said: “They could think it’s a friend, they could think it is someone their own age. But the reality is that it has been videoed and recorded and then been uploaded to child sexual abuse websites.

“Last year the rise was astronomical.”

The IWF also saw a dramatic rise last year in the number of reports of abuse material - 260,400 up from 229,328 in 2018 - which came from the public, police, its own investigators and software programmes called ‘crawlers’ that scour the internet for abuse images.