Child protection bodies have urged for stronger efforts to patrol child pornography after a research revealed that on an average it takes a month to take child abuse websites down from the net.
Research conducted by computer security experts at the University of Cambridge found the average time it takes for illegal websites to be blocked varied wildly, with child abuse images often staying online for many weeks.
Under "notice and takedown" schemes that persuade Internet companies to remove unlawful material hosted on their systems, child abuse sites remained online for an average of 30 days after being first reported.
In stark contrast, financial scam websites hosted on hacked computers were taken down in a mean time of just 3.5 hours.
The removal of child abuse websites in Britain is overseen by the Internet Watch Foundation (IWF), an independent body that works in conjunction with law enforcement and Internet companies around the world.
The study's researchers, Tyler Moore and Richard Clayton, said that the figures proved that current methods for removing illegal images from the Internet were not working.
"Our conclusion is that how long things stay available on the Internet is based on how persistent you are, rather than how wicked they are," Guardian.Co.UK quoted Clayton, as saying.
"The figures show that the IWF, in handing over the takedown to other organisations, is failing to deliver a service," he added.