Mark Sheridan Waden is charged with murdering his former partner, 45-year-old Priscilla Brooten, who vanished from the home they shared in Brisbane's north on July 5, 2018.
Her body has never been found.
Waden's trial will recommence on Wednesday after a new jury is sworn in, with the original jury having been discharged on Tuesday afternoon due to misconduct.
It emerged a juror had broken his oath and been researching elements of the case online, with defence counsel James Godbolt immediately applying for the jury to be discharged.
After an adjournment, a visibly frustrated Justice Peter Callaghan  reluctantly agreed.
Despite the juror being told by his peers what he was doing had been explicitly forbidden, Justice Callaghan said he could not be reassured the trial had not been contaminated.
"In one of the more difficult decisions I have had to make in this position, I will allow the application," he said.
"The factors which have been influential are firstly the lack of certainty as to what might have been said and, perhaps more importantly, that which might have been heard."
He said the juror who had broken his oath had to be regarded as unreliable in his assurances as to what he had said to the rest of the jury.
Justice Callaghan said short of interrogating every juror, the uncertainty so early in the trial weighed in favour of discharging the entire panel.
"We are at a very early stage of the trial which tends to favour an abundance of caution to allow the application and starting again."
He apologised to the jury for his decision.
"You will recall in the course of these directions I told you how important it was that for the integrity of the trial the jury in effect had to be sealed off from the rest of the world," he said.
"He took it upon himself to break that seal, with the result that there has been an application to discharge the entire panel.
"After truly anxious consideration I have decided to allow that application."
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