The Noble Park woman, aged in her 60s, was first reported missing by a neighbour last week on Saturday, June 14.
One of the woman’s neighbours had last seen her with an unknown man outside her home on Marna Court on June 7.
After being unable to contact her for a week, the neighbour raised the alarm with police.
Two days later, on Monday, June 16, police found the woman in Dandenong Hospital with injuries they believe were from a serious assault.
Victoria Police said they spoke with the woman, but she passed away yesterday evening in the hospital.
“At this time, the exact circumstances surrounding the incident that led to her being injured are still being determined,” they said.
“However, detectives from the Homicide Squad are investigating, and her death is being treated as suspicious.”
Police said her next of kin have yet to be notified of her death.
They have spoken with a 62-year-old man from Endeavour Hills, but he was released pending further inquiries.
The man was known to the woman who died, acording to police.
Anyone with more information has been urged to come forward.