Australian police said on Thursday they had arrested a 49-year-old woman over the deaths of three elderly people in August after they allegedly consumed poisonous mushrooms at a lunch hosted by her.

Victoria state police said they were searching the woman's house with the help of technology detector dogs -- trained to sniff out tiny electronic devices such as USBs and SIM cards, which are easy to hide, adding that the woman would be interviewed by police once the search was complete.

Don Patterson, his wife Gail Patterson and her sister Heather Wilkinson, became ill and later died after the lunch on July 29 in Leongatha, a small rural town around 85 miles southeast of Melbourne. A fourth man, Wilkinson's husband Ian Wilkinson, a pastor in a nearby town was released from hospital in September.

The mysterious deaths have gripped Australia. Deaths from consuming mushrooms are relatively rare in the country, which has several species including the "death cap" mushroom that are dangerous enough to poison and kill a human.

Detective Inspector, Dean Thomas, from the Victoria Police homicide squad said the woman arrested had been previously interviewed in relation to the events that unfolded, "Four people fell ill following taking part in a meal at a private residence there in Leongatha. Three of those people, Heather Wilkinson, Gail Patterson and Don Patterson, unfortunately passed away in hospital following taking part in that meal. The fourth person, Ian Wilkinson, was released from hospital in late September and I understand that he continues to recover."

He encouraged people not to speculate on the reasons for the arrest, coming more than 2 months after the incident, "Today's arrest is just the next step in what has been a complex and thorough investigation by homicide squad detectives and one that is not yet over. While we do want to provide timely updates about this matter it is critical that doing this does not adversely impact the current investigation or any future processes."