Prosecutors will continue questioning mushroom cook Erin Patterson as she returns for a fifth day in the witness box at her triple murder trial.

Patterson has entered a plea of not guilty regarding the murders of her former in-laws, Don and Gail Patterson, aged 70, and Gail’s sister Heather Wilkinson, aged 66, as well as the attempted murder of Ian Wilkinson.

She denies deliberately poisoning her four lunch guests on July 29, 2023 by serving them death cap mushroom-laced beef Wellingtons.

On Thursday, Patterson acknowledged before a jury of 14 that she had lied in her police interview about not owning a dehydrator and never having foraged for wild mushrooms.

She said she had a “stupid knee-jerk reaction to just dig deeper and keep lying” after being informed two lunch guests had died.

“I was just scared, but I shouldn’t have done it,” she told the jury.

During cross-examination, the prosecution focused on Patterson’s falsehoods, accusing her of lying about dehydrating mushrooms because she was aware that the truth could link her to the toxic lunch.

“I agree that I lied because I was afraid I would be held responsible,” Patterson said.

She also admitted she told Gail and Don Patterson she had a lump in her arm and was going to hospital to get it tested, which was untrue.

“They made me feel loved and cared for in the way that they were asking about my health and I didn’t want that to stop, so I just kept going,” she said.

Prosecutor Nanette Rogers SC accused her of using a “so-called cancer diagnosis” to get her guests to come over for lunch.

“I suggest that you never thought you would have to account for this lie about having cancer because you thought that the lunch guests would die?” the prosecutor asked.

“That’s not true,” Patterson replied.

Patterson will return for a second day of cross-examination on Friday as the trial continues.