A juror, whose personal research ended the ACT Supreme Court trial of Bruce Lehrmann, had three academic papers about sexual assault in his possession in the jury room.
Bruce Lehrmann was on trial after pleading not guilty to sexually assaulting Brittany Higgins at Parliament House in 2019.
He denies there was any sexual contact between the two.
The jury was about to begin its seventh day of closed door deliberations when the ACT's Chief Justice Lucy McCallum brought the trial to a close.
She told the court a juror had been found with an academic paper about sexual assaults, which was not part of the evidence, in the jury room, in breach of the rules.
The paper was found by accident during a routine tidy-up.
Jurors were warned by the chief justice every day of the trial not to do their own research.
Chief Justice McCallum said when the juror was questioned she was told the material had not been used or relied upon by any juror, something she said did not alleviate her concerns.
"It is appropriate in the circumstances to approach that evidence with some scepticism," she said.
"At the very least, the fact that the paper was located and taken into the jury room by the juror indicates that it may have influenced that juror's contribution to the jury's deliberations."
"The unfairness to both parties is manifest."
Chief Justice McCallum discharged the jury and aborted the trial.
In a footnote in her written judgement she revealed that after the jury was discharged, the juror had two more academic papers dealing with the topic of sexual assault.
The juror won't face any penalty because no ACT law has been broken.
The court has set a new trial date for February.
The jury had been sent back to deliberate further after telling the court on Tuesday they could not agree, but continued deliberations until the trial came to a close yesterday.
