An Australian woman who allegedly killed three people with a poisonous mushroom lunch has pleaded not guilty to murder.

Erin Patterson, 49, is facing three murder charges and two counts of attempted murder over the fatal beef Wellington meal in July last year.

Police also allege she tried to kill her estranged husband on three other occasions.

Ms Patterson has always maintained her innocence.

She has repeatedly said she did not intentionally poison her guests, and on Tuesday in the Latrobe Valley Magistrates Court was asked to formally enter pleas to the charges against her.

“Not guilty your honour,” she said, appearing via a video link.

The peculiar case has gripped the world and left a tight-knit regional Victorian community reeling.

Ms Patterson hosted a lunch at her home in Leongatha – a two-hour drive south-east of Melbourne – on 29 July. Attending were her former in-laws Gail and Don Patterson, along with Gail’s sister Heather Wilkinson and Heather’s husband Ian. Police have said Ms Patterson’s estranged husband Simon Patterson was also invited but could not make it at the last minute.

Hours after eating the meal, all four guests fell ill with what they initially thought was severe food poisoning. Within days, the Patterson couple, both 70, and Ms Wilkinson, 66, had died. Mr Wilkinson, 68, survived, after spending almost three months in hospital.

Police say they believe the four ate death cap mushrooms – which are highly lethal if ingested.

Ms Patterson was named as a suspect by police after she appeared unharmed after the lunch.

After months of investigation, detectives allegedly uncovered another three murder attempts Ms Patterson made against her estranged husband between 2021 and 2022, and in November she was arrested and formally charged with eight offences in total.

Her case will now be fast tracked to the Supreme Court in Melbourne for trial, with her first hearing scheduled for 23 May.