An eerie detail in the discovery of Samantha Murphy’s phone will raise more questions for investigators as they continue to search for the mum.

An eerie detail in the discovery of Samantha Murphy’s phone will raise more questions for investigators as they continue to search for the body of the missing Ballarat mum, according to a leading criminologist.

In a major development, police found Ms Murphy’s missing phone in a dam outside Ballarat on Wednesday last week.

Police are likely hoping it will lead them to the missing mum’s body.

According to 7News the phone is undamaged and in near-perfect working condition.

Forensic testing on the phone is ongoing but it could provide vital clues on the final movements of Ms Murphy.

Dr Xanthé Mallett from the University of Newcastle said the phone was a “major clue” in the case — and that she was “surprised” to hear it was in working condition.

“The police were searching for it obviously for almost four months, something took them to that dam,” she told Seven’s Sunrise on Tuesday.

“That hasn’t been disclosed what evidence or intelligence that was yet, but yes, this could absolutely offer new clues that will help find Samantha. As we know now, it is operational and downloadable.”

Patrick Orren Stephenson, 22, has been charged over the murder. Picture: Facebook

Dr Mallett said that was her “big fear when the phone had been found”.

“Four months later, I was concerned it would be beyond retrievable in terms of data,” she said.

“But we’re looking at possibly better geolocation data, depending on how long the phone was on before the battery died, for example, or it switched off. It could actually help build that picture of geolocation to help map where that phone moved and potentially, therefore, where Samantha moved.”

Dr Mallett said the “big question” would be whether the phone was dumped at the dam early on in the investigation or later.

“It’s very hard to say because I would expect a phone that’s been underwater or in mud for four months to be beyond retrievable,” she said.

“I would have been very surprised they could have got that phone operational, but it is. So does that indicate that it hasn’t been there for the entire four months? That’s yet to be seen. But it’s that timeline that the police will be working on and it’s certainly going to be essential in helping to develop that.”

Police found the phone in a dam outside Ballarat last Wednesday. Picture: Nine News

Dr Mallett said police would now be trying to get “as much information from that phone as possible”. “Obviously building that picture,” she said.

“I think that there may be potentially more witnesses that may come forward, because we know now about that dam, we know the phone is there. So I’m hoping that now that information is public other people may come forward and offer information as to who may have dumped that phone and when.”

Ms Murphy’s husband Mick said he knew it was his wife’s phone as soon as police called to tell him a phone was found.

There were subdued celebrations from police after the muddy phone in a wallet was pulled from the dam.

Police are still working to retrieve data from the phone.

“The physical properties of the phone will obviously be damaged but what’s behind it, those ones and zeros of data, will be retrievable,” cybersecurity expert Nigel Phair said.

“This is the game changer for the investigation.”

Ms Murphy with her husband Mick Murphy. Picture: Supplied

It comes after the man charged with Ms Murphy’s murder hired a top lawyer to represent him.

Ms Murphy, a beloved mother of three, vanished after going for a run on Sunday, February 4.

Patrick Orren Stephenson was charged with the 51-year-old’s murder in March.

Now Stephenson, 22, has hired top solicitor Paul Galbally from Melbourne law firm Galbally O’Bryan,The Australian reported.

Mr Galbally previously represented late Catholic Cardinal George Pell who was convicted but later acquitted of historic child sex charges.

Ms Murphy’s body has not been recovered despite extensive searches near her home in Ballarat.

On the Galbally O’Bryan website, Mr Galbally is described as having “developed a reputation as a leading defence lawyer” who has “run some of the country’s largest and most complex criminal cases”.

“His experience includes representing clients before public inquiries, royal commissions and in defence of Australian Securities and Investments Commission prosecutions,” the firm states.

“Paul is recognised throughout the legal profession for his judgment, sound strategic advice and discretion and is featured in Doyles Guide as one of Australia’s pre-eminent criminal defence lawyers.”

The discovery of the phone was a major breakthrough in the case. Picture: Supplied

Footage captured by the ABC showed police hugging, backslapping and shaking hands after finding the phone at the edge of the dam on Wednesday.

The device was found about 19 kilometres south of the Murphy family home.

Ms Murphy was last seen leaving her Eureka St house in Ballarat about 7am to go for a 14-kilometre run through the nearby Woowookarung Regional Park.

Police believed she had reached the Mount Clear area, adjacent to the park, about an hour after leaving home, but had not been seen or heard from since departing.

Subsequent searches by police and volunteers have failed to locate any trace of the missing mum.

In February, a huge group of volunteers combed through bushland after gathering at Ballarat’s Eureka Stockade Memorial Park – some bringing metal detectors and even a sniffer dog.

Later that month, police launched a targeted search of Buninyong Bushland Reserve involving a range of specialist units including mounted officers, dog squad and motorcyclists.

The search area was highlighted in “intelligence derived from a number of sources,” a police spokesperson said at the time.

Mr Stephenson, who has not entered a plea, is expected to appear at Ballarat Magistrates’ Court on August 8 charged with Ms Murphy’s murder.