BT is to begin technology trials within the next couple of weeks to block its Internet users from accessing illegal images of child abuse.
Details of exactly how BT intends to censor the sites remains sketchy. However, in a statement BT said the trial has the backing and support of the Home Office and will block access to several thousand Web sites on a blacklist compiled by the Internet Watch Foundation (IWF).
The IWF blacklist contains sites from around the world which contain images of child sexual abuse that are "illegal to view" in the UK, under the 1978 Child Protection Act.
According to BT, the list is "selected by the IWF on strictly legal grounds and is not based on any moral or subjective criteria. It covers only images of child sexual abuse. BT does not have any role in compiling the blacklist."
BT is also prepared to make its technology available to other ISPs on a wholesale basis and claims to be already is discussion with others service providers.
"BT does not pretend that this trial will offer a total solution to this problem, or that BT alone could provide such a solution, but we believe it is an important step in the right direction," the company said.
However, some sceptics were unsure about the effectiveness of the technology.
One insider said: "No sooner is a site blacklisted it then it changes its host or URL and re-appears somewhere else."