Misuse of the internet by jurors is posing a threat to the integrity of the jury system, the lord chief justice warned last week.

In a lecture to the Judicial Studies Board in Belfast, Lord Judge suggested jurors could be found in contempt of court and jailed if they search the internet for information relating to the case they are sitting on against a judge’s directions.

He said: ‘If the jury system is to survive... the misuse of the internet by jurors must stop.’Judge said the problem had not yet been fully addressed by the judiciary, as it had wrongly been assumed that it occurs rarely.

He said: ‘We cannot accept that the use of the internet, or rather its misuse, should be acknowledged, and treated as an ineradicable fact of life, or that a Nelsonian blind eye should be treated to it or the possibility that it is happening.’

On the impact of Twitter and other social media, Judge said he could find no statutory prohibition on the use of text-based remote transmission of material from a courtroom, but said it increased the potential for jurors to access prejudicial material.

He said: ‘We cannot stop people tweeting, but if jurors look at such material, the risks to the fairness of the trial will be very serious, and ultimately the openness of the trial process on which we all rely would be damaged.’ Judge stressed that judges are not ‘antediluvian’, and should welcome advances in technology, provided ‘that we are its masters, and it is our tool and servant’.