Don and Gail Patterson, both 70, died in hospital after their daughter-in-law Erin Patterson cooked them a beef wellington at her Leongatha home in Victoria's east on July 29.
Gail Patterson's sister Heather Wilkinson, 66, also died after the meal while her husband, Baptist church pastor Ian Wilkinson, was taken to hospital in a critical but stable condition.
Mr Wilkinson's family said on Saturday he had made "significant progress in his recovery" and had been released from Austin Hospital on Friday after almost two months of treatment.
"This milestone marks a moment of immense relief and gratitude for Ian and the entire Wilkinson family," they said in a statement.
The family thanked the Leongatha, Dandenong and Austin hospitals for the "unwavering dedication and exceptional care that played a pivotal role in Ian's recovery".
"The medical team's expertise and compassion have been a source of comfort and hope throughout this journey," they said.
The family also thanked the Korumburra community, church, friends, family, and colleagues for their support and prayers.
"This collective kindness has been a pillar of strength for Ian and the family, reinforcing the sense of unity and compassion that defines our community," the statement said.
Police believe the symptoms Mr Wilkinson and the deceased diners experienced were consistent with being poisoned by death cap mushrooms.
She was interviewed by police and released without charge but has since faced intense media scrutiny.
In a statement to police, Erin Patterson said she made a beef wellington using button mushrooms from a major supermarket and dried mushrooms bought at an Asian grocery store.
The 46-year-old 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.
Victoria Police have not commented on Ms Patterson's statement other than to say it was not one taken by officers, nor have they provided any updates on their investigation.
Mr Wilkinson's family appealed for privacy as he "continues his journey towards full recovery".
"We understand the public interest in Ian's recovery, but we urge everyone, including the media, to act with consideration and respect the family's wishes," their statement said.
