Surfers would have to register to be able to search for porn whether its legal or illegal sites
Search engines such as Google should do more to restrict access to online pornography, a government adviser on child internet safety has said.
John Carr says internet companies should block links which paedophiles use to find pictures of abuse.
It comes after a court heard April Jones's murderer Mark Bridger searched for child abuse and rape images.
Campaigners backed the call as Google said it has a "zero tolerance" policy to child sexual abuse content.
Mr Carr, a member of the government's Council on Child Internet Safety, said Google and other search engines should reset their default search setting to the safest option - blocking access to legal as well as illegal sexual images.
Those wanting to reach such material would have to register to search for other content, which would deter many from doing so, he argued.
Mr Carr told BBC Radio 4's Today programme internet search engines did prevent access to web addresses that contain child abuse images.
But he said one of the "key routes" paedophiles used to find content was through adverts containing "code words" that are placed on legal hardcore pornography sites.
He said: "Google's moral leadership is essential here. They are the biggest player in this space in the world. If they did it, I think others would have to follow."
http://www.bbc.co.uk/news/uk-22726004