Rape porn websites which depict violent sexual abuse should be banned, campaigners have told the government.

More than 100 experts and groups signed a letter calling for rape porn to be made illegal, as it is in Scotland.

A quick search on Google and other search engines brings up thousands of results for websites offering free video of disturbing content.

A member of Rape Crisis which helps victims of the sex crimes, Fiona Elvines said she was shocked by content only the click of a mouse away.

"Some of the material I will never forget," she said.

Google has come under fire for its stance on extreme content. Last month, a computer app went on sale in its Google Play store which featured jokes about rape. The search giant rakes in 30% of every sale in its online store.

Writing to prime minister David Cameron, campaigners said the easy availability of rape porn could make abuse more normal to some people.

It follows the conviction last month of paedophile Mark Bridger, who murdered April Jones, 5, in Wales. A large collection of sex abuse images were uncovered on his computer.

The letter said: "It is a serious omission not to have included images depicting rape and other non-consensual acts as they did in Scotland.

"This is not about making a distinction between real and simulated rape and child sexual abuse, with the latter being perfectly lawful to possess as long as it is 'fantasy' and actors are over 18.

"Permitting the possession of depictions of sexual violence as entertainment glorifies, trivialises and normalises such abuse."

A Downing Street spokesman said steps had already been taken to clamp down on illicit content.

He said: "Rape is an abhorrent crime and that is why this government has driven forward significant progress in tackling violence against women and girls.

"We share the public's concern about the availability of harmful content on the internet and have already taken steps to ensure there are better online filters to protect children.

"But we want to look at what more can be done and so the culture secretary [Maria Miller] has invited internet providers to a summit this month. We will look closely at the issues raised in this letter."