THE doctor who treated Australian mushroom killer Erin Patterson has revealed how he knew she was a “heinous” murderer within minutes.

Dr Chris Webster treated the Leongatha, Victoria, mother and now-convicted killer after she took herself to hospital following the infamous lunch.

Nearing 50, Patterson prepared a beef wellington laced with deadly death cap mushrooms and served it to four guests, resulting in the death of three in July 2023.

Webster he had spent the next morning treating two of the poisoned four only for Patterson to turn up complaining of gastro, he told the BBC.

Within minutes, Webster knew she was a cold-blooded killer.

The doctor said: “I thought, ‘Okay, yep, you did it, you heinous individual. You’ve poisoned them all’.”

Patterson was convicted on Monday of killing her 70-year-old in-laws, Don and Gail Patterson, and Gail’s sister Heather, 66.

This home cook was found guilty of trying to murder Ian Wilkinson, a local pastor and the husband of Heather, by Victoria’s Supreme Court.

Webster had first treated Heather and Ian at Leongatha Hospital the next morning after the lunch with intense gastroenteritis-like symptoms.

Initially, it seemed like a widespread case of food poisoning, but after questioning his patients, it was suspected that the meat in the beef wellington was the source.

Webster said: “I did ask Heather at one stage what the beef Wellington tasted like and she said it was delicious.”

The doctor took Heather and Ian’s blood samples and then sent them for analysis to a larger town with better facilities than the small rural Leongatha Hospital.

Soon after, he received a call from the doctor treating the other two who were poisoned – Don and Gail – at Dandenong Hospital.

She said it was the mushrooms, not the meat, and Webster’s stomach dropped.

Webster had hooked Heather and Ian with fluids, but quickly changed tack as he realised their life was on the line.

He knew he needed to save their failing livers and prepared to send them to a larger hospital where they could get better care.

But then a person presented themselves to the hospital claiming they had gastro symptoms.

Webster asked Patterson for her name and said when he heard it: “The penny dropped… it’s the chef.”

The doctor quizzed the chef about where the mushrooms had come from – Woolworths, she said.

It was with that answer that Webster knew she was guilty.

But the doctor said that made no sense as the supermarket giant would have stringent food safety standards.

Webster also said Patterson didn’t seem worried about the danger Heather and Ian – lying only metres away – were in.

He then sent Ian and Heather off in an ambulance to Dandenong Hospital, saying he tragically knew they wouldn’t return.

When he returned, Patterson had checked herself out against medical advice.

After desperately trying to call Patterson but being unable to reach her, Webster called the cops.

He said: “This is Dr Chris Webster from Leongatha Hospital. I have a concern about a patient who presented here earlier, but has left the building and is potentially exposed to a fatal toxin from mushroom poisoning.”

At the trial, Patterson said she had been caught off guard by the information about the deadly mushrooms and went home to pack an overnight bag and feed the animals.

She also had a “lie-down” before returning to the hospital.

When she finally did, Webster tried to get her to also bring her children, who the chef claimed had eaten leftovers.

In court, Patterson said she was “concerned that they were going to be frightened.”

Days later, Patterson was caught on CCTV trying to cover her tracks by dumping the food dehydrator she used in her twisted murder plot.

Wearing a long coat and sunglasses, Patterson is seen unloading the food dehydrator at the Koonwarra Transfer Station on August 2, 2023 – an apparent attempt to erase evidence linked to the deadly beef wellington meal.

And in a chilling image also released by the court, the meal that left her family dying in agony is laid out next to forensic evidence bags.

The annotated photo was taken during toxicology testing at the Victorian Institute of Forensic Medicine.