Victoria Police say items recovered in bushland on Wednesday are not believed relevant to the search for missing woman Samantha Murphy.
Ms Murphy, 51, failed to return home on Sunday morning after heading out for her regular run in a nearby state forest.
Emergency service vehicles temporarily blocked an entrance to the Woowookarung Regional Park, across the road from her home, after items were discovered in bushland on Wednesday.
In a media release, police indicated that the items found were not connected to the search.
Investigators examining footage from the area believe that Ms Murphy was running along Eureka Street, and was captured on CCTV near the intersection of Warrenheip Road at around 7:16am, running towards Yankee Flat Road.
Police are now asking residents in the area to review their CCTV footage from between 7:00am and 11:00am.
Friends and loved ones of Ms Murphy remain hopeful she will be found soon.
"The main thing I've seen is on social media. Everyone has shared and shared it," Ballarat local and friend Chris Stapleton said.
"My husband and I thought we'd come out [to search] because if it happened to any of my children or daughters we would hope the community would be out as well. It's just so sad.
"Mick [Ms Murphy's husband] and your beautiful children, I just hope Sam comes home for you."
Paula Heenan, director of the Ballarat Centre of Music and the Arts and a friend of Ms Murphy, described her as someone who could be relied on.
"Samantha is a woman you can count on for anything, especially for her three gorgeous children who she loves fiercely," she said.
"She supports them in all of their endeavours and as a family they sign up to be involved in every event and performance they can.
"Samantha is a wonderful help backstage at shows and looks after not only the children in her care, but the other adults around her to ensure that everybody is well cared for and happy."
Police have described Ms Murphy's disappearance as out of character as she was familiar with the trails she intended to run and walked or ran in the area every day.
The hot weather on Sunday, with temperatures reaching 36 degrees Celsius in Ballarat, in an area of Victoria littered with thousands of disused mine shafts, has increased concern for her welfare.
Ms Heenan said the situation felt surreal.
"We just can't fathom what might have happened or how it happened, how somebody can just disappear," she said.
"It is just indescribable ... how bizarre it is."
Search expanded
A public Facebook group called Find Samantha Murphy has been set up for community members to communicate areas they have searched.
It has attracted more than 4,000 members.
City of Ballarat mayor Des Hudson said he was impressed but not surprised by the extensive community response.
"We generally come together as a city when there are different crises upon us," he said.
"I think for someone who still has a young family there is always that empathy from our community that wants to do more."
Ballarat resident Courtney, who asked for her surname not to be published, joined the search on Wednesday.
"Everyone is doing what they can," she said.
She said she had some concerns for her own safety and the safety of other volunteers who were going off trails into bushland, due to disused mine shafts in the historic gold mining area.
"Some people don't know the area ... of course there is a danger when you're out walking by yourself," she said.
"From a volunteer's perspective, it would've been nice to see the SES and volunteers going out in groups, rather than off you go, search this area."
Forest Fire Management Victoria, CFA, SES, and Victoria Police's dog squad, mounted branch, solo unit, and air wing are continuing the official search led by police search and rescue.
The search area expanded to areas including bushland around Black Hill, Brown Hill, and Nerrina on Tuesday afternoon.
"The area of search isn't completely remote. We are on the outskirts of Ballarat and it is not that far from urban areas as well," Acting Inspector Lisa Macdougall said on Monday.
Victoria Police previously said the search area was based on data from Ms Murphy's phone and areas she was known to run.
Ms Murphy's phone was on and with her when she disappeared.
It is not known what informed the expansion of the search area to Black Hill, but Victoria Police said the search area was "fluid" with police responding to particular areas when and where needed.
A community information noticeboard outside the Buninyong Police Station is encouraging people to search tracks and sides of tracks for anything, including a phone, watch or earpods.
Hope of finding Samantha alive
Day four of the search resumed at first light on Wednesday with still no trace of Ms Murphy's whereabouts.
Victoria Police said the search and rescue unit was grateful for the multitude of community volunteers who had joined the search effort.
People who want to help are advised to read the public information board at the front of the Buninyong Police Station in Scott Street which contains information on suggested search areas.
Police are urging volunteers to pair up, ensure they have water and a phone, and not to put themselves or others at risk.
Ms Murphy is described as Caucasian, about 173 centimetres tall, of slim build, and with shoulder-length blonde hair.
She was last seen wearing black exercise leggings and a brown singlet.
Anyone who sees Ms Murphy, or has information on her whereabouts, should contact CrimeStoppers, or triple-0.