The chances of finding missing Melbourne mother Elisa Curry alive in the bush after at least four days is remote, police say.
Police admit they're baffled by the disappearance of the 43-year-old who went missing at the weekend from a holiday house at Aireys Inlet, a small town on the Great Ocean Road.
Widespread air, land and water searches have failed to find the avid runner, who regularly jogged long distances from the property, which was again swarming with police on Thursday as the investigation continued.
Inspector Peter Seel told reporters it's possible Ms Curry went for a run and has become disoriented in bushland.
However, the likelihood of finding her alive in the bush after at least four days is remote, he added.
"Just so many days without food, water, shelter and just the elements," makes it a grim outlook, he said.
Investigators aren't ruling out suspicious circumstances.
The last confirmed sighting of Ms Curry was by a neighbour, who saw her get into bed on Saturday night after the pair had a "personal" conversation.
"The neighbour and her husband were over there, they left and then the wife came back," Inspector Seel said.
"It's a personal matter."
But he said there was no incident on Saturday night that caused the woman distress.
Ms Curry's neighbours visited after another friend had already been at her house for dinner.
Husband David Curry and their three children watched the AFL grand final in Melbourne before returning to the holiday house on Sunday to find her missing and lodging a report with police.
Text messages on Saturday night between the couple, showed no reason for concern, Inspector Seel said.
There has been no activity on Ms Curry's phone since 10.30pm on Saturday and she did not use her Fitbit for several days before she went missing, limiting police ability to track her more recent movements.
Thursday's search included scouring vacant homes, sheds, gardens and door-knocking properties within a 300-metre radius of the house where she was last seen and efforts are due to resume on Friday.
The disappearance has rocked the close-knit community.
"It's just really scary I think because Aireys is such a small little town and it just doesn't happen," resident Laura Stocks told the AAP on Thursday.
"It's scary, it's just really eerie."
A police caravan will be set up in the town at the weekend, with a detective on hand to take information.