The Ministry of Justice (MoJ) has sacked four officials for misusing social networking sites at work, it has been revealed.

A Freedom of Information (FOI) request revealed that in the past 18 months, the MoJ has dismissed four officials and issued three written warnings over misuse of sites such as Facebook, YouTube and Twitter.

The department said that staff are not allowed to access the sites for personal reasons while at work, but confirmed that access is allowed if officials “are able to provide a strong business case that shows they need to use these media to perform their role”.

The MoJ has its own Twitter feed and YouTube page to help communicate its activities.

The same FOI request also revealed that in the same period the Metropolitan Police has charged four officers with formal misconduct and given 18 written warnings related to misuse of social networking tools.

The civil service has sought to improve its use of social networking in recent years, with permanent secretary for communications Matt Tee telling Civil Service World last year that the Cabinet Office guidance on microblogging – criticised for being overly long – was “bloody good”.