“It has come to my attention that contrary to directions I’ve given you have undertaken research into the case,” Chief Justice Lucy McCallum told the court on Thursday morning.

“That information has made its way into the jury when it ought not to have.

“It may be that no harm has been done but that is not a risk I can take.”

The court heard this prohibited research was uncovered when one of the court officers, who was cleaning the jury room, accidentally bumped one of the juror’s folders onto the floor.

When the officer picked up the folder, which had a clear plastic front, he noticed part of a title of an academic research paper into sexual assault sticking out of the folder.

Justice McCallum said that her associates then identified the article in question.

“The identity of the paper found by my associates has been confirmed in evidence this morning by the juror in question,” she said.

“The subject matter of the paper is indeed sexual assault.

“The juror this morning gave an explanation that the document had not been used or relied upon by any juror.”

However Justice McCallum said she was sceptical about that evidence. “During the course of the trial ... I must have given the jury at least 17 warnings and prohibitions on undertaking any research of their own.

“This is an unexpected and unfortunate outcome in this trial,” she said.