The search will be ramped up for the missing body of Samantha Murphy, as the biggest mystery in the case remained where the Ballarat mum’s corpse has been hidden.

Police will allege the mother of three was murdered by the son of a former AFL player in a “deliberate attack” on the day she headed out for her morning run five weeks ago.

The 22-year-old man was charged over Murphy’s death and appeared briefly in court late Thursday, but cannot be named after his lawyer applied for a suppression order.

His lawyer argued that releasing the Scotsburn man’s name could cause prejudice to his right to a fair trial, and his client had been suffering poor mental health since he was arrested.

However, a hearing scheduled for Friday could reveal the alleged murderer’s identity as media organisations apply to the court, seeking to identify the alleged killer.

Victoria Police Chief Commissioner Shane Patton said the man was being charged over an “intentional act” and “not a hit and run”.

“We are alleging a deliberate attack that has caused the death of Samantha,” Patton said on Thursday.

He said police would step up their efforts to find Murphy’s body, which was of “primary importance”. The arrested man has so far refused to disclose the whereabouts of Murphy’s remains.

No trace of the 51-year-old has been found despite extensive searches of dense bush, private land and walking tracks in the Ballarat region which is known for its many deep mine shafts.

“Our investigators will be not stepping back at all, in fact we’ll be going even harder to try and recover her body,” Patton said.

“Investigations will continue at a very heavy pace.

“Doing everything we can to locate Samantha’s body for the family is absolutely vital.”

Detectives from the missing persons squad arrested the alleged murderer, who is not linked to the Murphy family, at his home about 6am on Wednesday. He was charged with murder on Thursday.

The man was returned to custody and will next face court on August 8.

Police are not looking for anyone else in connection with the homicide.

Murphy, a mother of three, has not been seen since February 4 when she left home to go trail running on a Sunday morning.

Her family was told of the arrest on Wednesday night and informed of the murder charge on Thursday afternoon.

Samantha Murphy has been missing since she went for a Sunday run on February 4.

Murphy’s husband Michael said he was relieved.

He described the past few weeks as “s—house” and was emotional as he said the community had rallied around his family.

“It’s like someone’s let the pressure valve off sort of thing,” he said.

“It hasn’t been a good nearly five weeks.”

Patton commended Murphy’s family for withstanding the scrutiny they had been under since the investigation was triggered and thanked volunteers who had helped with the search.

“Samantha’s disappearance had a profound impact on the Ballarat community,” he said.

“Some cases, some disappearances, some murders, bring out outpourings of grief and we have seen that here.”

Counter terrorism police, the missing persons squad and other specialist officers have been involved in the probe.

Detectives have been working with telecommunications technicians to track the route she travelled after confirming she had a smart watch and phone with her.

A vigil will be held in Ballarat on Friday night near Murphy’s home.