Social media users are being warned not to prejudice criminal cases prior to trials beginning.

The UK’s Attorney General Dominic Grieve will be publishing advisory notes to help prevent social media users from committing acts of contempt of court.

Attorney General Dominic Grieve says that the advisories, which have previously been issued only to print and broadcast media outlets on a "not for publication" basis, are being released to help ensure that fair trials are taking place.

Grieve said that he has changed the policy to stop the public from falling into legal pitfalls by publishing comments on court cases in a prejudicial manner.

Grieve hopes that the guidance will prevent ‘legal novices’ from publishing statements that could cause a trial to be abandoned.

Several people were fined just last year for publishing on a social media site the name of a woman who was raped by football player Chad Evans. Recently Peaches Geldof publicly apologized for tweets she published that were related to a case.

The attorney generals advice will apply to court cases in both England and Wales.

Grieve says that he hopes to prevent people without any legal training from publishing remarks that could technically be contempt of court.

"Blogs and social media sites like Twitter (News - Alert) and Facebook mean individuals can now reach thousands of people with a single tweet or post. In days gone by, it was only the mainstream media that had the opportunity to bring information relating to a court case to such a large group of people that it could put a court case at risk. That is no longer the case and is why I have decided to publish the advisories that I have previously only issued to the media. This is not about telling people what they can or cannot talk about on social media; quite the opposite in fact – it's designed to help facilitate commentary in a lawful way. I hope that by making this information available to the public at large, we can help stop people from inadvertently breaking the law, and make sure that cases are tried on the evidence, not what people have found online. This change also brings more openness to government's dealings with the media so that both sides can be accountable to the public for what they do and say," Grieve said.

The attorney general's office on average issues about five advisories a year. In 2013 it has issued 10 so far due to high-profile court cases. The office has issued advisories on cases such as the murder of Tia Sharp (News - Alert), Sgt Danny Nightingale's court martial and the arrest of Christopher Jefferies.

Trials have been abandoned in the past by judges due to misleading information being published. So far no Twitter postings have halted court proceedings.

The attorney general says that he only issues advisories "when it's clear that things are starting to go wrong … [and] when I have a clear sense that problems are developing."