The 51-year-old Ballarat woman was last seen leaving her home on Eureka St, to go for a run in the Canadian State Forest, on the morning of February 4.
Detectives from the Missing Persons squad, with help from a range of specialists from Victoria Police, NSW Police and the Australian Federal Police, began a new search in Grenville on Tuesday.
"Since February, police have regularly undertaken a range of enquiries and small-scale searches as part of the current investigation," Victoria Police said in a statement.
"We are not in a position to supply further specific details of today's operational activity at this time."
A similar search in March uncovered Ms Murphy's phone, buried in the mud on the edge of an agricultural dam.
Ms Murphy's disappearance led to an outpouring of grief in the Ballarat community and the nation, leading to an influx of volunteers who joined the early stages of the search.
Police have asked the public not to help this time.
Police in March charged 23-year-old tradesman Patrick Orren Stephenson with the murder of Ms Murphy.
Stephenson will face court in November, after prosecutors asked for a delayed committal mention to go through an "extensive" evidence brief including reams of CCTV footage.
Stephenson is the son of Orren Stephenson, who played 15 AFL games for Geelong and Richmond between 2012 and 2014.
Ms Murphy's family has been advised of the search.