Two heartbroken family members of missing Ballarat woman Samantha Murphy have revealed their theory on what has happened to the mother-of-three.

The 51-year-old disappeared after going for a run in the Canadian State Forest in Victoria, Australia, on February 4, with police describing her disappearance as “out of character”.

It has now been 15 days since she disappeared.

Murphy’s uncle and aunt have since speculated that the only explanation for her disappearance is foul play, fearing she was abducted by a deranged stalker.

“It’s just like she’s gone off the face of the earth. There’s nothing,” aunt Janice Robson told the Daily Mail.

“You’d think the police dogs would have been able to pick up her scent. They should have been able to pick up where she ran into that forest.”

Crews scoured dense bushland in the Canadian State Forest for missing woman Samantha Murphy.

Clues Samantha Murphy’s family believe indicate foul play

Last week, after a week-long search in bushland, false CCTV hopes and empty leads, Victoria Police Chief Commissioner Shane Patton announced the case was now “suspicious”.

“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,” he said.

Murphy was believed to have been wearing an Apple Watch and was carrying her phone when she disappeared.

Her phone reportedly pinged in the nearby suburb of Buninyong, but no further information has come to light over the ping.

Samantha Murphy is 51 and described as tall with blonde hair, last seen wearing a brown singlet.

That has left the family scratching their heads, suggesting that the fact Murphy’s phone hadn’t made communication with a mobile tower since she went missing didn’t bode well.

“She would never switch that phone off … that phone was always hooked up,” her uncle Allan told the Daily Mail.

Family’s theory behind Samantha Murphy disappearance

Allan gave more background on the day Murphy disappeared, revealing she was supposed to be back for a meeting on the morning she vanished.

Murphy was supposed to be back at around 9am, according to Allan. By 11am, two hours after her scheduled return home, Allan said her husband Mick made the phone call to police to report her missing.

Michael (Mick) Murphy, the husband of missing woman Samantha Murphy, has appealed for any information from members of the public about the whereabouts of his wife.

Police confirmed she was supposed to attend a brunch the same morning and never showed up.

Allan speculated that she could have been stalked by someone who knew her routine.

He said a possible motive might have been a robbery that went wrong, claiming it may have been known the Murphys were financially stable.

“Mick [Murphy’s husband] had so many cars he couldn’t fit them in his garage,” Allan said.

His wife added: “I don’t think it’s an opportunist. I think it’s been someone who has been stalking her. Someone who she didn’t even know was stalking her.”

The couple said if she was taken, she “would have put up a bloody good fight” and would have used her running fitness and speed to get away if she had the chance.

On Wednesday, Patton said there were still no leads and the investigation is now headed by the missing persons squad.

“It’s suspicious, whether that means there’s foul play involved or not, I don’t know, but obviously detectives are investigating a matter where a woman’s been missing for a significant period of time.”

Allan said police have not been forthcoming with any information to the family other than what the public knows.

He said any information they have they’ll “sit on it” and they don’t want to “spook” anyone.

Forensic expert’s theory about missing mum

A forensic expert who has analysed some of Australia’s most infamous criminals told Sky News that despite his expertise in criminal forensics, he has “never encountered” a case like Murphy’s.

Forensic psychologist Tim Watson-Munro said what baffled him about the case is that there has been “no evidence” to examine, explaining there is usually a small clue left behind for investigators to work with.

“I’ve never encountered a case like this where someone ostensibly goes for a run and they’re never seen again. It’s very unusual ... There’s no clues at all,” he told Sky News.

He highlighted that there were a “number of possibilities” of what happened to Murphy, but that having a happy family life before disappearing only adds more questions.

This has led Watson-Munro to look at one concerning theory on what happened to Murphy.

“One of them is that she had been stalked for a while. I’ve done a lot of profiling. Stalkers love routine of their potential victims,” he said.

He theorised that a stalker may have abducted Murphy, suggesting the perpetrator could know about “evidence and covering their tracks”.

He went on to suggest she may have been abducted in a van or car and taken away from the potential crime scene that police have been combing.