British bloggers and Twitter users could face police visits leading to "severe sanctions" if they tweet or blog in defiance of court orders, the government's most senior law officer has warned.

Attorney General Dominic Grieve, giving evidence to a joint committee of MPs and Lords on privacy and injunctions and reported by, said that material posted on blogs and Twitter had the potential to go viral and "suddenly start to spread around the world in an astonishingly fast speed."

In a warning to tweeters and bloggers who decide to publish on the internet in defiance of court orders - such as super injunctions - Grieve said they "had better beware."

Adding: "One day somebody is going to end up being prosecuted and discover to their consternation that in fact there are some quite severe sanctions which can be visited upon on them for what they have done."

Last year, a super injunction was put in place by footballer Ryan Giggs to stop the press from reporting about aspects of his private life, but Giggs was revealed as the "mystery footballer" by thousands of Twitter users, who all technically committed an offence by breaking the super injunction.

Grieve continued: "I certainly know that there have been instances where bloggers have been visited by or rung up by the police and told you shouldn't be doing that, you stop blogging immediately and they have done so."

Finally, Grieve said that Twitter users and bloggers would receive the same treatment as traditional journalists: "The criteria I am likely to apply to a blogger or tweeter is exactly the same as I'm going to apply, I think, largely to anybody else, any national newspaper."