Jurors who look up the grisly details online of cases they are involved in could be prosecuted under a new criminal offence, and media websites forced to take down previous stories of crimes before they go to court - under measures proposed in a consultation by the Law Commission.

Courts could get new powers to order websites to take down any previous articles about crimes, including articles like tributes to missing children, in order not to prejudice a trial of someone involved in the offence.

The new proposals on reform of the contempt of court laws are attempts to protect defendants from "trial by media" and prevent jurors from making unfair decisions based on what has been posted online.

Newspapers and broadcasters are currently banned from allowing comments or linking to previous speculation or stories when court proceedings are active - usually after a suspect is arrested.

The Huffington Post UK closes all online comments and does not link to previous stories after a suspect is arrested by police, but stories from before the arrest do remain online.

Jurors could have their mobile phones or laptops confiscated when they arrive at court, under the proposals being put forward.

Judges are worried that the existing laws do not criminalise all the different types of research online a jurors could potentially do about the cases - and a new criminal offence of "intentionally seeking information relevant to the case" that they are trying may be required.

A number of jurors have previously caused a string of upsets because of their use of social media and research online in the past few years.

Theodora Dallas who carried out internet research at home while sitting at a criminal trial was jailed for six months for contempt of court, after she told other jurors what her research had revealed about a defendant on trial at Luton Crown Court in July 2011.

The judge aborted the trial after learning about her research and the High Court said Dr Dallas had "deliberately disobeyed" the trial judge's instructions not to search the internet.

Another incident concerned lorry driver Stephen Pardon, 42, who on a jury considering allegations of a multimillion-pound metal theft plot in 2011. He disclosed details to one defendant and "attempted to do so" to another defendant, the High Court heard.

And in June 2011, juror Joanne Fraill, who contacted a defendant via Facebook, causing a £6m drugs trial to collapse, was been jailed for eight months for contempt.

Announcing the consultation, the Law Commission said: "The internet, and the opportunities it offers media organisations and individual citizens to publish information and comment to vast audiences instantaneously, have radically changed the communication landscape.

"Blogs, Twitter, Facebook, Google+ and other social networking sites enable ordinary people to engage in public conversation and express their views on a scale and at a speed that has never before been possible.

"Once information has been released on the web, it is very hard to contain.

"And, unless steps are taken to remove it, it remains easily available to anyone with access to the internet in a way that is not true of printed materials.

"The commission is asking what safeguards can be put in place to prevent jurors searching for, and being able to find, potentially prejudicial material during the course of a trial, irrespective of when it was published."

The Law Commission's consultation runs until 28 February 2013.