A CSC report published earlier this week detailed offensive material on BNP-supporting YouTube accounts, blogs and internet forums run by members and self-professed supporters of the BNP.
The sites host and link to material that displays support for violence, admiration of the Third Reich, extreme racist views and denial of the holocaust.
The report is a response to BNP calls to be treated as a mainstream political party.
The report's authors state that "it would be unacceptable" if any of the three main parties failed, as the BNP have, to distance themselves from and denounce similar views if they were posted on sites run by their supporters.
As a by-product of the report, new evidence was uncovered that the Race Relations Act had been breached, but the CSC has said that, because many of the bloggers remain anonymous, it may be difficult for them to bring legal action without police involvement.
CSC director Douglas Murray said: "This report shows members and supporters of the BNP continue to hold and express the vilest racist, anti-semitic, homophobic and sexist views - shocking even to those of us who thought our opinion of the BNP could never be lower."
As BNP MEPs Nick Griffin and Andrew Brons entered the European Parliament today in Strasbourg, anti-racist campaign group Hope Not Hate delivered a "not in our name" petition to the Parliament with thousands of signatures from members of the British public stating that the BNP does not represent their views.
