TOP judges have ordered a probe into the trial of a woman jailed for a brutal hen party attack — amidst claims she had 22 mutual Facebook friends with a member of the jury.

In a case which raises question marks over the impartiality of trial by jury amidst increased social media use, Emma Mitchell, 30, of Douglas Place, Blackburn, says a series of small town links to the juror means she did not receive a fair trial.

The inquiry is thought to be the first of its kind in the country and has been ordered by judges at the High Court.

Mitchell was convicted of wounding with intent to cause grievous bodily harm at Preston Crown Court in December last year, and later jailed for four and a half years.

But Appeal Court judges have now taken the rare step of ordering an investigation by independent watchdog, the Criminal Cases Review Commission (CCRC), into what the juror had known about Mitchell at the time of her trial.

Mitchell's barrister, Kenneth Hind, said evidence had surfaced that the juror had written about her court duty on Facebook and had ‘liked’ a comment by a friend, which stated: "If it was me I would send them all down."

The trial judge had refused to discharge the juror after she admitted knowing the landlady of the Farthings pub, in Blackburn, where Mitchell first confronted the victim of her attack, he added.

It later emerged that the landlady had managed another pub where Mitchell had committed previous criminal damage and violent disorder offences, the court in London heard.

Mr Hind said that, as well as the Facebook connection, it had also come out that the juror's daughter saw Mitchell arrested for the wounding offence and was friends with a member of Mitchell's family.

Witness statements claimed the juror had previously drunk at the same pub and once lived near Mitchell.

"Blackburn is not the smallest town, but it is not the biggest," Mr Hind added. "There was a very real danger the juror could have been biased."

Mitchell was jailed for a boozy attack on Chantelle Zoe Phillips in a Blackburn flat after a hen party, which left her victim bloodied, needing stitches and permanently scarred, in February, last year.

The court heard that Mitchell had hit her victim repeatedly with a weapon, believed to be a bottle, when she was off-guard and after telling her: “I have never liked you, Chantelle.”

Mr Justice Kenneth Parker said: "It is alleged in witness statements that there is significant Facebook linkage between the juror in question and the applicant. At the moment that linkage seems indirect but, nonetheless, it is submitted that it is substantial."

Usually jurors cannot be questioned on why they reached a verdict or what took place in their deliberations during a trial.

But the appeal judge, sitting with Lord Justice Pitchford and Judge Francis Gilbert QC, directed the CCRC to quiz the juror on what she knew about Mitchell and to establish if there was any risk of bias.

The judge added: "In the circumstances we have decided to adjourn the appeal and we also believe that it is appropriate in this case that the matter be referred to the CCRC in order that they should be able to carry out an investigation."

Mitchell's appeal against conviction is expected to be heard in February 2013.