The woman who cooked the lethal mushroom lunch that killed three people has been arrested by Victoria Police.

Erin Patterson, 49, was arrested by homicide squad detectives at her home in Leongatha, in Gippsland, just after 8am on Thursday.

A search warrant was executed at her Gibson Street home with assistance from Australian Federal Police technology detection dogs.

Detective Inspector Dean Thomas said the arrest was the “next step” in the “complex and thorough” investigation which was ongoing. No charges have been laid.

“Once the search of the premises is complete today, [Patterson] will be interviewed by homicide squad investigators,” he said.

Thomas said the case had been subject to “incredibly intense levels of public scrutiny and curiosity” in the past three months.

“I cannot think of another investigation that has generated this level of media and public interest. Not only here, in Victoria, but also nationally. And internationally,” he said.

But he urged the public and media to keep in mind that “at the heart of this, three people have lost their lives”.

“These are three people who by all accounts were much beloved in their communities and are greatly missed by their loved ones.” Thomas said.

He said the tragedy may “reverberate for years to come.”

Heather Wilkinson, 66, her sister Gail Patterson and brother-in-law Don Patterson, both 70, died after falling ill following a lunch at Erin Patterson’s home in Leongatha in July.

Wilkinson’s husband Ian, 68, spent weeks in hospital critically ill. He was released only in late September.

Police believe the symptoms the four diners experienced were consistent with being poisoned by death cap mushrooms.

Homicide detectives previously named Patterson as a suspect as she cooked the beef Wellington lunch that is believed to have led to the deaths.

She has previously been interviewed by police and was released without charge.

In a statement to police obtained by the ABC, Patterson said she made the beef Wellington using button mushrooms from a major supermarket and dried mushrooms bought at an Asian grocery store.

She said she ate a serving and later suffered bad stomach pains and diarrhoea, contrary to the suggestion of detectives that she did not fall ill.

She has previously denied any wrongdoing.

Victoria Police have not commented on Patterson’s statement other than to say it was not one taken by officers.

– with AAP