A juror who carried out internet research on a defendant has been jailed for six months.

The Divisional Court, headed by the lord chief justice Lord Judge, today found university lecturer Theodora Dallas (pictured) guilty of contempt of court, following a case brought by the attorney general Dominic Grieve QC.

Dallas was a juror in a case at Luton Crown Court in July 2011. The court heard that in breach of instructions given by the jury officer, a warning contained in a written notice, her jury oath and directions from the judge, she carried out internet research on the defendant and shared the information with other members of the jury while the jury was in deliberation.

Her actions caused the trial, which related to charges of grievous bodily harm, to collapse and a retrial to be ordered. The defendant was convicted.

The trial related to Barry Medlock, charged with two co-defendants with causing grievous bodily harm with intent, contrary to section 18 of the Offences Against the Person Act 1861.

The allegation was that over an extended period of time he and the co-defendants tortured the victim, beat him with various objects, set him alight and poured caustic soda with boiling water over him, causing him to be scarred for life.

The two co-defendants pleaded guilty, and Medlock was tried alone. Details of a previous conviction for actual bodily harm were allowed to be adduced in evidence under bad character provisions.

However on the third day of the trial a juror reported that Dallas had read online that the defendant and his accomplice had also been previously charged with rape (Medlock was acquitted), and had told the other jurors.

Dallas denied that she had deliberately conducted research and had understood the directions related only to the use of Facebook.

Commenting on the case, Grieve said: ‘I take no pleasure in bringing such cases but they send an important message. By her action Ms Dallas halted a trial which was near completion and, aside from the financial implications, her actions resulted in the victim in the case being forced to return to court and give evidence for a second time.

‘There can be little doubt that repeated warnings were given to Ms Dallas and her fellow jurors as to the prohibition on conducting research into the case which they were trying.’

Grieve added that three weeks earlier, juror Joanne Fraill had been prosecuted for discussing a trial on Facebook. Fraill was given an eight-month custodial sentence.

The case highlights the increasing concerns over the impact of the internet in the jury system.

In a speech last November, the Lord Chief Justice warned that misuse of the internet posed a threat to the integrity of the jury system. ‘If the jury system is to survive…the misuse of the internet by jurors must stop,’ he said.

The case also highlights how the courts are clamping down on jurors who do not carry out their duties appropriately. Last month juror Matthew Banks was jailed for two weeks after being labeled ‘frivolous’ for going to see a musical in London after telling a Manchester court that he was ill.