A desperate search for a Melbourne grandmother who vanished during her regular morning walk has ended in heartbreak, with police confirming the 73-year-old has been found dead.

Janet Knight, who was living with a rare and aggressive form of dementia, disappeared after leaving her home in Keilor East on Sunday morning, sparking an urgent search involving police, family members and the wider community.

Tragically, her body was discovered in waters off Riviera Road in Avondale Heights on Wednesday afternoon, three days after she was last seen.

“Sadly, the body has been identified as missing woman Janet,” Victoria Police confirmed in a statement.

Police said her death was not being treated as suspicious.

Janet had left her Steele Creek Drive home shortly before 7am on Sunday, with CCTV footage later capturing her walking along Hoffmans Road towards Keilor Road in Niddrie at approximately 7.38am.

An enthusiastic walker who knew her neighbourhood well, Janet regularly enjoyed the walking trails around Steele Creek and the Maribyrnong River.

But alarm bells rang when her daughter, Nicole Knight, discovered her mother had left home without her phone, wallet or Fitbit, something she described as completely out of character.

“This is very unusual behaviour for her, totally out of character,” Nicole told reporters during the search.

“The fact is, she left her phone, she left her wallet and all her belongings behind.”

Nicole explained that her mother had been diagnosed with an uncommon form of dementia that significantly affected her ability to communicate, although her memory had been less severely impacted.

“She will often know what she wants to say, but can’t actually get the words out,” Nicole said.

“She’s always been quite calm and accepting that this is the disease that she was dealt and is really understanding of that.”

Despite her condition, Janet remained physically active and loved spending time outdoors.

“She will walk rain, hail or shine,” Nicole said, explaining that Steele Creek was among her mother’s favourite walking spots.

As the days passed, concerns grew about Janet’s safety, particularly given the cold, wet and windy weather and the possibility that heavy rain had flooded walking tracks near local waterways.

In an emotional public appeal, Nicole and her brother Chris pleaded for help bringing their mother home.

“We love you,” Nicole said in a heartbreaking message to her missing mother.

“You can come home.

“Please reach out to anyone that you see walking past and tell them that you need help because you’ve got sons, daughters, grandkids and family that are all waiting and love you.”

Sadly, the reunion her family had so desperately hoped for was not to be.

While Janet’s body was discovered in the water, authorities have not publicly confirmed the circumstances or cause of her death.

Victoria Police thanked everyone who helped spread the word during the search and extended their condolences to Janet’s grieving family.

“We would like to extend our appreciation to the media for their assistance during the search and our thoughts are with the family during this difficult time,” police said.

For Janet’s loved ones, what began as an ordinary Sunday morning walk has ended in an unimaginable loss, leaving a family mourning a much-loved mother and grandmother.