'No leads' yet in disappearance of Ballarat mother, police say

Chief Commissioner Shane Patton said the investigation is still ongoing at a Melbourne press conference Wednesday morning, days after the Missing Persons Unit took over the case.

"We don't have any further developments with the investigation into Samantha Murphy," he said.

"I do want to say, because I have heard some veiled criticism, (the Missing Persons Unit) has been involved since the start - we knew this had the potential to be a significant and prolonged investigation when we couldn't find any trace of Samantha early on.

"This has been really thoroughly investigated from the start, and still is.

"We keep saying it's not suspicious, but when someone's been missing for this period of time, we have no trace, well clearly there must be some suspicions there because we haven't been able to locate her.

"It's certainly unusual when we haven't been able to locate any trace of her, or any other evidence, within that period of time.

"Whether that means there's foul play involved or not, I don't know, but detectives are investigating a matter where a woman has been missing for a significant period of time - call it unusual, call it suspicious.

"It's so traumatic for the family, for her friends, and again, even though we're having this conversation here, I'd urge people not to speculate what has or hasn't happened.

"We are working with the family, working with the friends, and Missing Persons are tracing and stepping through timelines, looking at CCTV, examining many information reports we've received from the public

"It's still early days but the concern is that we still have no leads - we've committed significant additional resources from Crime Command to assist Missing Persons because of the CCTV capture and the exploration of where that may be available, we have literally hundreds of info reports, obviously of varying different quality, we have to wade through those."

It follows a week-long search with hundreds of volunteers spread across eastern Ballarat and Buninyong.

She was last seen leaving her house for a run or walk on Eureka Street at 7am on Sunday, February 4 - there were grave fears for her welfare given it was a 36 degree day in Ballarat.

Ms Murphy's husband and daughter made an emotional appeal for information last week, with Mr Murphy telling the media "people don't just vanish".

Ms Murphy was last seen wearing a brown or maroon top and black leggings.

Anyone with information is urged to phone Crime Stoppers on 1800 333 000 - anyone who sees her should phone triple-zero immediately.