No breakthroughs as search for mother enters sixth day

Police are keeping up the scale of their search for missing 51-year-old Ballarat mother Samantha Murphy, appealing for dashcam vision in the area.

A Ballarat mother's family and community are growing increasingly desperate six days into the search for her, as specialist detectives are called in.

About 40 local police will be assisted by detectives from the Missing Persons Squad in the regional Victorian centre on Friday, hopeful of finding any sign of 51-year-old Samantha Murphy.

Ms Murphy - known to family and friends as a mentally and physically strong woman - was last seen leaving her Eureka St home in Ballarat East about 7am on Sunday to go for a run. 

Search crews are expanding their focus to the Buninyong area on Friday after working through the Eureka and Canadian state forest areas.

Ms Murphy was last seen leaving her Eureka St home at Ballarat East about 7am on Sunday.

Police have struggled to make any breakthroughs with authorities enlisting the help of the Missing Persons detectives, experienced in investigating disappearances and conducting complex bushland searches and with more resources to draw on.

CCTV released on Wednesday initially thought to have shown Ms Murphy running on Eureka St actually depicted someone else and was irrelevant to the investigation.

"That didn't hamper or impact our investigation in any way," Inspector Bob Heany told 3AW on Friday.

"It was within our area of operations anyway so it's just enabled us to eliminate the fact that Samantha had gone that way."

Mr Heany again appealed for residents in the suburbs of Ballarat East, Canadian, Eureka, Buninyong and Mount Helen to review any CCTV or dashcam they have from 7am onwards on Sunday for any sign of Ms Murphy.

"One of the challenges we have is the area is so remote that there's not a lot of businesses or residential CCTV available," he said. 

Investigators have not identified any suspicious or sinister circumstances to Ms Murphy's disappearance, and Detective Acting Superintendent Mark Hatt confirmed homicide detectives are not involved.

"We do hold significant concerns for Samantha's welfare at this stage and that is growing as the day progresses," Det Supt Hatt said.

Search crews have canvassed a large area of Ballarat looking for the mother of three, with State Emergency Service and Country Fire Authority personnel helping police comb the city's east, the Canadian Forest area and Mount Helen in recent days.

Fears are growing for the missing mother with the search in its sixth day.

The local community has also helped with the search, with many on foot, others riding bicycles, on horseback or in four-wheel drives, to pick through scrub on the roadsides.

Police are expected to again call in drones from the air wing to aid the search.

Detectives are working with telecommunications technicians to identify the route Ms Murphy travelled after confirming she had a smartwatch and her phone on her.

Mr Heany said Ms Murphy's movements on Sunday morning were in line with what she'd normally do

"Samantha's very fit - both physically and mentally - she would cover up to 14 to 15km on her runs," he said.

"She'd normally due back from her run within a couple of hours and alarm bells went up when she didn't return from that run."

Ms Murphy's distraught eldest daughter Jess on Thursday called for help to bring her mother home.

"I know she's out there somewhere, so if you could please continue to search for her to give us something to work with, we'd really appreciate it," she told reporters.

The missing woman's husband Mick added: "People just don't vanish into thin air.

Someone has got to know something."

Anyone with information about Ms Murphy's disappearance should contact Crime Stoppers.