A juror accused of contacting a defendant through social networking site Facebook is being prosecuted for contempt in a London court, in what is being seen as a legal first.
Prosecutors want the High Court to jail Joanne Fraill for allegedly exchanging messages on the site with the female defendant, Jamie Sewart, causing a multi-million-pound drugs trial to collapse last year.
British taxpayers were left picking up a bill of £6 million after the judge was forced to discharge the jury.
The case began today and is being heard by the Lord Chief Justice, Lord Igor Judge - the head of the judiciary and the same judge who earlier this year allowed the authorised use of Twitter in the reporting of some court cases.
At the time, Lord Judge warned courts must be satisfied live text reporting does not interfere with the proper administration of justice.
Sitting with two other senior judges, he was told at the start of the hearing that Ms Fraill (40) had formally admitted contempt of court. But Sewart (34) who was also in court, denies contempt.
The alleged contact occurred after Sewart had already been acquitted in the major drugs trial, but while the jury had still to reach verdicts on other defendants in the case.
Ms Fraill is also accused of researching the defendants on the internet, despite strict instructions by the judge to the contrary.
In a speech last year, Lord Judge warned that jurors could go to jail if they searched the internet for information on defendants. If found guilty, the pair could each face up to two years in prison.
The trial continues.
Later the same judges will hear an appeal by one of the defendants, convicted drug dealer Gary Knox. He is challenging his conviction on the basis of alleged jury misconduct.
Knox (35) was jailed for six years for conspiracy to commit misconduct in a public office. The court was told that he bought sensitive information on drug dealers from police in return for a £20,000 BMW and Premier League match tickets.
A police officer, Phil Berry (44) who received the gifts and admitted the same charge, was jailed for four years.