Australian police on Thursday arrested the woman at the center of a mushroom meal mystery that left three people dead and a local preacher fighting for his life.

The arrest of Erin Patterson, 49, is the latest twist in a saga that has gripped the nation and thrust the spotlight on the small rural town of Leongatha, 110 kilometers (70 miles) southwest of Melbourne.

"Homicide squad detectives have arrested a woman this morning as part of their investigation into the deaths of three people following an incident in Leongatha earlier this year," Victoria police said in a statement.

Police said they had executed a search warrant at Patterson's address in the morning. 

She has not been charged.

Patterson served the mushrooms as part of a beef Wellington dish on the afternoon of 29 July to her estranged parents-in-law Don and Gail Patterson, local Baptist pastor Ian Wilkinson, and his wife Heather.

Later that night, the two couples were taken to hospital with food poisoning symptoms as their health rapidly deteriorated.

Within a week, three of them were dead

Police believe their symptoms were consistent with those caused by eating highly toxic death cap mushrooms.

Of the four, only 69-year-old pastor Wilkinson survived after spending nearly two months gravely ill in hospital. He was released on 23 September.

He appeared for the first time in public in early October at a memorial for his wife, with a local newspaper describing him as "frail-looking" and "using a walking frame".

Police had named community newsletter editor Patterson as a suspect soon after the fateful meal.

Patterson always insisted she was innocent, reportedly saying in August that she had unwittingly bought the mushrooms from an Asian grocery store and that the poisonings were accidental.

"I am now devastated to think that these mushrooms may have contributed to the illness suffered by my loved ones," she said in a statement provided to Australian media at the time.

"I really want to repeat that I had absolutely no reason to hurt these people whom I loved."

A memorial service for Don and Gail Patterson was held at the end of August. Reverend Fran Grimes told the congregation that the community was trying to "shield and protect the family from heartless speculation and gossip".

Death cap mushrooms sprout freely throughout wet, warm parts of Australia and are easily mistaken for edible varieties.

They reportedly taste sweeter than other types of mushrooms but possess potent toxins that slowly poison the liver and kidneys.