Child abuse sites reported daily

Four out of five of these sites are commercial operations aiming to cash in on the shocking trade among paedophiles, the Internet Watch Foundation (IWF) said.

The charity has passed the details of 2,092 sites to Interpol, national police forces and other authorities across the world so far this year.

It revealed the figures as internet companies including AOL, Tiscali, Yahoo! and MSN join forces to mark the organisation's first awareness day.

The IWF operates a hotline offering help to all UK internet users confronted by images of children being sexually abused. Research by the charity has found that one in 20 adult internet users - some 1.5 million people - have been exposed to such images.

Chief executive Peter Robbins said new information also revealed the severity of abuse images continued to increase. The IWF found more than a third of all child sexual abuse sites contain images of the the most severe forms of abuse, including rape and assault.

Mr Robbins said: "Our analysts witness the results of terrible sexual abuse being inflicted on very young children around the world and then circulated online.

"With the help of the online industry, the 28 hotlines we work with around the world and our law enforcement colleagues, the public can help us to remove these websites and end the abuse that is perpetuated every time the images are viewed."

The IWF said images of child abuse hosted by UK-based websites had been all but eradicated in the past decade. But the nature of the internet means images can still be accessed from other countries where enforcement is not as strict or pro-active.

Advertisements carrying details of the IWF's work will run on several high-profile sites as part of the awareness day.