British civil servants, who spend too much time on online social networking sites like Facebook or Twitter at work or post inappropriate comments from home, may face disciplinary action or the sack, a media report said.

According to the 'Daily Mail', government departments and officials planning 2012 London Olympics have issued written guidelines to staff members detailing their restrictions on using the online sites; they are paying outside consultants to conduct courses for employees on the do's and dont's of how to behave on Facebook and similar sites.

The Olympic Delivery Authority distributed a guide to all employees stating, "Facebook, Linked-In, Twitter have become very popular... and offer significant business benefits...

Their use poses risks both to the data on the ODA IT system... and to the users of the sites and ODA."

A letter to staff says they are allowed to use social networking sites in lunch breaks but warns: "You must not publish content about London 2012."

In fact, one police force censured eight employees last year after it caught them using police computers to chat to their friends online.

A local authority disciplined a member of staff who used the websites to discuss what he was doing in his social life while he was supposed to be off sick. And, another council caught staff using special software to get around a ban on using office computers to tweet on Twitter and 'update their status' on Facebook during working hours.

Last year, Sir John Sawers, the head of British spy agency MI6, was left exposed by a personal security breach after his wife published intimate photos and family details on Facebook.

This led to all government staff who were undergoing developed vetting -- required if they were to handle top-secret documents -- being warned against posting personal details online which could leave them open to blackmail.