A British online watchdog group, the Internet Watch Foundation (IWF), warned that child pornography peddlers are using ‘disguised websites’ that appear like adult porn sites to upload child abuse photos and videos.

IWF, explaining this in its 2011 Annual Report, said the offensive content can be accessed only by following a particular, pre-determined digital path.

Internet Watch Foundation director of communications Emma Lowther said it is hiding in plain sight.

"Most people who click on the site will see legal content, but if you follow the digital breadcrumbs, it will give you access to the [illegal] content," added Lowther.

Child porn dealers are said to use a variety of online techniques, including anonymous message boards, to let their fellow peddlers know how to access the hidden content, according to Lowther.

It is said to be a legitimate technique, often used by shopping websites which remember users when they return.

According to the IWF this porn website disguising technique was used 579 times in 2011.

The foundation added that almost 75% of child victims were aged 10 years or younger.