Detectives from Victoria Police's missing persons unit have taken charge of the investigation into the disappearance of Ballarat woman Samantha Murphy, with the search in its sixth day.
Official search crews and volunteers have been combing through swathes of bushland around Ballarat in an effort to find the 51-year-old mother of three, who failed to return after leaving her home about 7am on Sunday for a run.
When she missed a brunch appointment her worried family called police, who began an ever-widening search.
On Friday, police confirmed the missing persons unit had taken charge of the investigation and the search would be scaled back over the weekend.
In the early afternoon, crews from the CFA were asked to withdraw from the search.
Detective Acting Superintendent Mark Hatt said he wanted to make clear that as of Friday morning police had "nothing immediate to indicate there is anything sinister behind Samantha's disappearance".
"We haven't received any information relating to her movements from the moment she left [her] home address on Sunday morning," he said.
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Detective Acting Superintendent Hatt said that despite the CFA being pulled back, specialist teams would continue to search.
"In relation to the volunteers, they will be scaled back over the weekend," he told ABC Statewide Drive.
"And if the need arises where additional intelligence or information comes in that we need to scale back up, we'll certainly do that."
He said missing persons investigators had more resources and experts that could help with the search.
"There will certainly be additional detectives from crime command attending the Ballarat area today and in coming days," he said.
The search has been largely focused on the Ballarat East, Canadian and Mount Helen areas, particularly east of Geelong Road.
Searchers are today focusing on the area around Buninyong.
"We've covered a lot of area so far, so we're just expanding our search area," Inspector Bob Heaney said.
"Our search will be ongoing and our commitment to locating Samantha is there.
"We'll continue the search until we find her."
Police are now asking anyone who may have driven through the area with dashcam footage from 7am to 7pm on Sunday to come forward.
Land owners and farmers in the area have also been asked to check properties and sheds for anything that might help with the investigation.
Loading...Ms Murphy's husband Mick appealed to the public on Thursday to keep searching and come forward with information.
"People don't just vanish into thin air," Mr Murphy said.
"Someone's got to know something.
"Whether it be any little thing that you might think's relevant, just call the police. Let them know."
Her daughter, Jess Murphy, described her mother as someone who wouldn't stop fighting.
"Mum's a really strong woman and she's far too determined to give up this fight," she said.
"If you could please continue to search for her, to give us something to work with, we'd really appreciate it."
On Wednesday, police released CCTV footage showing a person running down Eureka Street, however the image has now been ruled out of the investigation after a local resident came forward to identify themselves in the footage.
Ms Murphy is described as a regular runner and familiar with the often isolated roads around her home.
She was well-known to locals who would often see her on her runs.
The Murphys own a local panel beating business, Inland Motor Works, where Ms Murphy works in administration.
Friends have also described her as closely involved in the arts and the local community.
One of Ms Murphy's friends, Virginia O'Loughlan, said the tense wait for news was taking a toll.
"It's a rollercoaster of a nightmare at the moment. I can't sit still," she said.
"Our kids went to school together, that's where I first met Sam … we'd often catch up.
"Everyone absolutely adores Sam. She is the backbone of a lot of community organisations.
Ballarat police officer Lisa Macdougall told ABC Statewide Drive that while police had ruled out CCTV vision of a runner, they would still like the community to keep checking their cameras.
She asked anyone with dashcam or CCTV vision from the search area to review footage and contact police about anything unusual.
"It's particularly important for us to scour everything that's out there, any knowledge, and take that into account so that we can really assess what evidence we have," Acting Inspector Macdougall said.
"I would suggest to the community ... that rather than making an assessment of their own, they bring it to the attention of police."
Acting Inspector Macdougall said police had been "inundated" with information from the people trying to help.
A Facebook group set up by locals dedicated to the search quickly grew to 10,000 members.
Many of these people have volunteered to head out into the Woowookarung Regional Park and help emergency services with the search.
Ms Murphy is described as Caucasian, about 173 centimetres tall, of slim build and with shoulder-length blonde hair.
On the morning she went missing she was wearing black exercise leggings and a brown singlet.
Anyone who sees Ms Murphy or has information that can help with the investigation, should contact triple-0 immediately.