An Australian woman has been jailed for life, with no chance of release for at least 33 years, for murdering three relatives and attempting to kill another with a toxic mushroom meal.

The jail term, one of the longest ever handed to a female offender in Australia, means Erin Patterson, 50, will be in her 80s before she can apply for parole.

A Supreme Court judge stated Patterson's crimes fell into the worst category of offending and involved an elaborate cover-up.

Patterson killed her in-laws Don and Gail Patterson, both 70, and Gail's sister Heather Wilkinson, 66, after serving them a toxic beef Wellington at her home in Victoria in 2023.

Heather's husband Ian Wilkinson, a local pastor, survived the lunch after recovering from a coma and has ongoing health issues related to the poisoning.

Patterson's estranged husband Simon Patterson was meant to attend but cancelled last minute due to his belief that his wife had been trying to poison him.

Patterson has consistently maintained her innocence, claiming the toxic death cap mushrooms were added accidentally.

She will serve three consecutive life sentences for the three murders and an additional 25 years for the attempted murder of Mr. Wilkinson.

During sentencing, Justice Christopher Beale emphasized the gravity of her actions and the need for maximum punishment, though he stated the harsh prison conditions influenced his decision to allow a possibility of parole.

Patterson faces significant risks from other prisoners due to the notoriety of her case and currently spends 22 hours a day in her cell.

Survivor Ian Wilkinson expressed gratitude to the legal system, reflecting on the loss of his loved ones and urging kindness among people. He also noted that the court's decision to allow television coverage of the sentencing was a first in its history, reflecting the high public interest in the case.

Erin Patterson has 28 days to appeal her sentence and the guilty verdicts for triple murder and attempted murder.