Erin Patterson denies 'wild goose chase' over mushroom origins

Triple-murder accused Erin Patterson has been grilled over where she sourced the mushrooms for her toxic meal, denying she sent health authorities on a "wild goose chase".

Crown prosecutor Nanette Rogers, SC, on Wednesday continued her cross-examination of Patterson by asking about the origins of dried mushrooms contained in the beef Wellingtons she served.

The 50-year-old's former in-laws Don and Gail Patterson, both 70, and Gail's sister Heather Wilkinson, 66, died after consuming the meal, while Heather's husband Ian became seriously ill but survived.

READ MORE: Suspected arsonist dies in hospital five months after Melbourne blaze

Patterson has pleaded not guilty in the Victorian Supreme Court to three charges of murder and one of attempted murder.

She denies deliberately poisoning her lunch guests on July 29, 2023 when she served them the death cap mushroom-laced dishes.

Patterson said the first time she mentioned dried mushrooms being in the meal was in a call with her brother-in-law Matthew Patterson while she was in hospital days after the fatal lunch, when he asked where the ingredients had come from.

"I said possibly the Oakleigh area," she told the court sitting in regional Victoria.

Patterson was pointed to evidence from doctors and others who suggested she told them she bought the mushrooms in Oakleigh, Clayton or Glen Waverley, all suburbs in east Melbourne.

Patterson agreed with the prosecutor that she told Department of Health manager Sally Ann Atkinson the mushroom packaging did not look professional, was in a small snack-sized bag that was not resealable and didn't have a printed label.

READ MORE: Worst in 60 years: Major alarm bells ringing on economy

"You gave detailed (recollection of the) packaging, even though you couldn't give details about the store," Dr Rogers said.

"Correct," Patterson responded.

But she denied an accusation she wanted it to sound like they were not commercially produced mushrooms.

Rogers suggested Patterson used the information to make her story about buying death cap mushrooms from an Asian grocer "seem more believable".

"I suggest you were deliberately vague about suburbs when asked about it," Rogers said.

READ MORE: Ex-NRL player not guilty of rape, admits to separate sexual assault

"Incorrect," Patterson responded.

"Your story kept changing," the prosecutor said.

"I don't think it did," Patterson replied.

In her police interview, Patterson said she had been "very, very helpful" with the health department during their investigation, but Rogers disputed that.

"You sent them on a wild goose chase to find this Asian grocer," she said.

"Incorrect," Patterson replied.

Patterson was asked about leftovers she fed her children a day after the fatal lunch, telling the court: "I was pretty clear it was the meal minus the mushrooms and pastry, so not the same."

"You told the lie about feeding leftovers to your children because it gave you some distance from a deliberate poisoning," Rogers suggested.

"I don't see how it could, but I disagree anyway," Patterson responded.

The accused previously gave evidence she had booked a pre-surgery appointment for a gastric bypass at Enrich Clinic in Melbourne after wanting to do something about her weight.

On Wednesday, Patterson was provided with a statement from the clinic's manager, which the prosecutor said was a "cosmetic dermatology clinic that does not offer gastric bypass".

She accepted the prosecutor's proposition the clinic has never offered gastric bypass surgery and only conducts examinations and procedures relating to the skin and its appendages.

She was also questioned about the dehydrator she purchased from Woolworths to dry mushrooms.

The prosecutor showed a photo Patterson had taken of button mushrooms on the dehydrator two days after buying the machine, suggesting she was "testing how to dehydrate mushrooms using these button mushrooms".

"I dehydrated the mushrooms to eat them," Patterson responded.

A second photo showing death caps on the dehydrator was then shown, with the prosecutor suggesting Patterson had practised using button mushrooms first to not waste the death caps. 

"I don't think they had anything to do anything with each other," the accused said, denying she wanted to preserve the death caps.

The trial continues.

LISTEN NOW: The Mushroom Trial Say Grace is the latest podcast from Nine and The Age. Join journalists Penelope Liersch and Erin Pearson as they take listeners inside the case that's grabbed global headlines. You can listen on Apple here and Spotify here.