A juror in the trial of an Australian woman accused of killing three relatives by feeding them poisonous mushrooms has been removed for possible misconduct.

Erin Patterson – who has pleaded not guilty – is on trial for the murder of three people and the attempted murder of another, after they ate lunch at her home in July 2023.

The male juror was discharged on Thursday after the judge found there was a “reasonable possibility” he had discussed the case with family and friends.

The judge told the court there was no definitive evidence that the man had discussed the trial with outsiders, but reminded the remaining jurors they should only talk about the case “in the privacy of the jury room”.

Justice Christopher Beale also told the jury that confidential juror discussions were “vital to the administration of justice”.

Fifteen jurors – three more than usual – were selected for the trial, which began a fortnight ago in Victoria and was expected to last six weeks.

After the court has heard all the evidence, the jury will be reduced to a final 12 people who will deliberate over the verdict.

Prosecutors allege Ms Patterson “deliberately poisoned” her guests “with murderous intent”, after inviting them for lunch “on the pretence she’d been diagnosed with cancer”.

Ms Patterson’s defence team says it was a “terrible accident”, and that she lied to police and disposed of evidence because she “panicked” after unintentionally serving poison to family members she loved.