A jury in July found Erin Patterson, 51, guilty of murdering three elderly relatives of her estranged husband and attempting to murder a fourth in the state of Victoria in 2023.

She was sentenced to life in prison with a non-parole period of 33 years, one of the longest sentences ever given to a woman in Australia.

Documents released on Wednesday by the Supreme Court of Victoria showed Patterson on Monday applied for leave to appeal her conviction.

The seven grounds of appeal included that a “fundamental irregularity” occurred while the jury was sequestered.

Local media, citing the court, reported the jurors stayed in the same hotel as police and prosecutors for the majority of their deliberations.

Patterson also said various pieces of evidence introduced, including cell tower location data and messages from Facebook friends, were either irrelevant or unfairly prejudicial.

Additionally, she said she was subjected to an “unfair and oppressive” cross-examination, and the prosecution changed its case during its closing address to imply there was a motive for murder, causing a substantial miscarriage of justice.

Her application for leave to appeal has been accepted by the appeals registry, the court said, but must be approved by the court for the appeal to proceed.

Patterson maintained her innocence throughout the 11-week murder trial and said the poisoning was accidental.

Prosecutors separately filed an appeal against her sentence in October, describing it as “manifestly inadequate”.

Patterson was convicted of killing her mother-in-law, Gail Patterson, father-in-law, Donald Patterson and Gail’s sist, er Heather Wilkinson, in a case that gripped the country and drew international attention for its unusual circumstances.

The jury of 12 found she lured them to lunch at her home in Leongatha, a town of about 6,000 people, some 135 km (84 miles) southeast of Melbourne, and poisoned them with beef Wellingtons containing death cap mushrooms.

She was also found guilty of the attempted murder of Ian Wilkinson, Heather’s husband, who survived the 2023 meal.