Birmingham City Council could be facing legal action after it installed an internet filtering system that breaks religious discrimination rules.

The system, Bluecoat WebFilter, allows computer users to view sites on a variety of religious organisations, including Christianity, Islam and Hinduism, but blocks those that cover "occult practices, atheistic views, voodoo rituals or any other form of mysticism".

Lawyers from the National Secular Society are examining the system and have said they may take legal action under religious discrimination laws.

"We suspect that the Council have not set out to contravene or reverse their own equal employment policies and that this problem results from someone in the Council acting in a thoughtless way," said National Secular Society president, Terry Sanderson.

"We just hope that common sense prevails and the Council resolves the matter without submitting themselves needlessly to legal action which would bring more unwelcome publicity."

A city council statement said the authority had a "long-standing internet usage policy for staff".

It added: "We are currently implementing new internet monitoring software to make the control of internet access easier to manage.

"The aim of this is to provide greater control for individual line managers to monitor internet usage, and for departments, such as trading standards and child protection, to gain access, if needed, to certain sites for business reasons."