Police are yet to reveal if they have found any trace of missing Ballarat mother Samantha Murphy, after scores of officers spent the day scouring dense bushland.

Specialist officers and local police descended on Enfield State Park, about 25 kilometres from the regional Victorian city, early on Thursday for what they said was a “significant search” for the 51-year-old mother of three.

Murphy has not been seen since leaving her home in Eureka Street, Ballarat, to go for a run in Canadian State Forest on the morning of February 4.

In March, police charged 22-year-old tradesman Patrick Orren Stephenson with her murder at Mount Clear on the day she went missing. He will return to court in August.

Stephenson is the son of Orren Stephenson, who played 15 AFL games for Geelong and Richmond between 2012 and 2014.

There were multiple reports on Thursday that Stephenson is refusing to cooperate with police.

Victoria Police said the latest search would focus on an area “highlighted by intelligence derived from a number of sources”.

Cadaver dogs from NSW joined the search for Samantha Murphy for the first time on Thursday. Photo: AAP

Friends and other locals who have previously helped to scour bushland in the region looking for any sign of Murphy were asked not to join in on Thursday.

“Today’s search in the Enfield State Park involves a significant number of detectives from the missing persons squad and police from a number of specialist areas,” Detective Acting Superintendent Mark Hatt said.

Other crews included search and rescue, the public order response team and the mounted branch. For the first time, specialist cadaver dogs from NSW were also brought in.

“Since Samantha’s disappearance over two months ago, a range of searches and other inquiries have been undertaken in the Ballarat area as part of this investigation,” Hatt said.

“This includes extensive large-scale searches such as we have planned this week, but also smaller targeted searches focused in very specific areas.

“I want to assure those in the Ballarat community that police remain focused on doing everything we can to return Samantha to her family.”

On March 20, investigators carried out a similar search in the Buninyong area, about 11 kilometres from Ballarat. It was called off after about eight hours with no trace of Murphy’s body found.

On Thursday, about 50 searchers turned their attention to Enfield State Park. They combed it for any sign of Murphy’s body, with one dog dashing around and inspecting small pits in the ground believed to be mine shafts.

The park is difficult terrain – an area that once housed tents and diggers now dotted with abandoned gold rush-era mine shafts that have been reclaimed by wildlife and dense bush.

Thursday’s search was expected to go beyond 4pm (AEST).

The Murphy family was told of the latest search, which follows unsuccessful efforts in the Canadian State Forest.

In the days after Murphy vanished, her husband Michael and eldest daughter Jess issued an emotional plea for information about her whereabouts.

“Mum we love you so much and we miss you and we need you at home with us; please come home soon,” she said.

“I can’t wait to see you and to give you the biggest hug when I do, and to tell you off for giving us so much stress.”

Jess said her mother was a “really strong woman” and “far too determined to give up this fight”.

“I know she’s out there somewhere, so if you can please continue to search for her to give us something to work with, we’d really appreciate it,” she said.

The central Victorian city has been rocked by a series of tragedies this year, including a mine collapse that claimed the life of miner Kurt Hourigan, the death of mother-of-five Rebecca Young and bushfires in surrounding areas.

On April 5, 23-year-old Hannah McGuire was found dead in a burnt-out car at nearby Scarsdale. Her former partner Lachlan Young, 21, has been charged with her murder.

Ballarat locals will rally on Friday night as an act of solidarity in the fight to end violence against women. A description of the event on social media said women did not feel safe in the city.

-with AAP