Erin Patterson was found guilty of killing three family members as she served them a lunch laced with poisonous fungi.

An Australian court has confirmed that an appeal hearing for Erin Patterson, commonly referred to as the “mushroom murderer,” will be held in August.

The Supreme Court of Victoria announced on Friday that the hearing will take place on August 19 and 20. Patterson’s lawyers formally applied to appeal her life sentence in November, arguing that there had been a “substantial miscarriage of justice” during her trial.

Patterson was sentenced to life in prison in September after being found guilty of murdering three of her estranged husband’s relatives by serving them a lunch laced with poisonous fungi.

During the two-day hearing, the court will also consider an appeal from prosecutors, who argue that her sentence, which allows her to be considered for parole after 33 years, is “manifestly inadequate”.

Prosecutors unsuccessfully argued during the trial that her sentence should have been life imprisonment without parole.

In July, a jury found Patterson guilty of killing her estranged husband’s parents after serving them a lunch of beef Wellington laced with toxic mushrooms.

The case attracted worldwide attention, with more than 250 journalists registering for updates from the court, and the judge deciding to broadcast the sentencing live.

Both Gail Patterson and Donald Patterson died in August 2023. Patterson was also found guilty of murdering Gail’s sister, Heather Wilkinson, who died that same month, and of attempting to kill Wilkinson’s husband, Ian. He spent seven weeks in hospital following the poisoning and received a liver transplant.

Patterson is appealing her conviction on seven grounds, including what her lawyers described as a “fundamental irregularity” relating to the sequestration of the jury, who stayed in the same hotel as key figures in the case, including a police witness and two prosecutors.

Patterson’s lawyers also argue that several pieces of evidence presented during the trial were either irrelevant or unfairly prejudicial, and that the prosecution’s cross-examination of her was “unfair and oppressive”.

Patterson maintains her innocence, arguing that the poisoning was accidental.