Dezi Freeman, 56, was still at large on Friday following the fatal confrontation on Tuesday at a property in Porepunkah, about 300km northeast of Melbourne.
Victoria Police arrested his 42-year-old wife Mali and a 15-year-old on Thursday night following an operation at an address in Chandler Court near the town's centre.
"Those searches have been completed, the interviews have been conducted, those people have been released," Victoria Police Chief Commissioner Mike Bush told reporters in Wangaratta on Friday.
"There may or may not be charges that follow."
On Friday morning, the street was quiet, and the curtains on the property, where two cars were parked out front, were drawn.
Mr Bush said the search was continuing for Freeman, who is married with three children, and police are investigating possible sightings.
"There have been alleged sightings which we're exploring. We can't confirm that they are of him, but if you think you see him, let us know. We'll explore it," Mr Bush said.
It comes as a concerned friend Marlie Thomas said Freeman had become more withdrawn in the days before the fatal shootings.
She attends the local Our Lady of Snows Catholic church alongside Freeman and his wife.
"We knew he was withdrawing a little bit," she told AAP.
"We said, 'we've got to keep a closer eye on him'."
She urged Freeman to "please come in, hand yourself in".
More than 450 police officers have been deployed to the small rural town as part of search, investigation and support efforts, backed up by the Australian Federal Police, with more officers from NSW, South Australia and ACT on their way.
A Special Operations Group helicopter had been circling the property about 8.30am on Friday, and a convoy of police cars, including an armoured Bearcat vehicle was seen soon after.
"We are not leaving here until this person is in custody," Mr Bush said.
"In fact, if that person is listening, it really is time to lay down your firearms and give yourself up so that we can all bring this to a safe conclusion."
Freeman - also known as Desmond Filby - fled into bushland after he allegedly killed Detective Leading Senior Constable Neal Thompson, 59, and Senior Constable Vadim De Waart, 35, at a Porepunkah property on Tuesday.
Prime Minister Anthony Albanese on Friday paid tribute to the dead officers, calling them heroes and offered his thoughts to the injured officer.
"This guy (Freeman) is clearly dangerous. He's on the run and we want him caught," Mr Albanese said.
A 56-year-old detective was among a group of 10 attempting to serve a search warrant relating to alleged child sex offending when he was wounded.
He remains in hospital awaiting a second surgery after being shot in the lower body.
Police are yet to seize any weapons belonging to the fugitive, with Mr Bush believing his firearms licence had been revoked at the time of the incident.
Wintry conditions, including damaging winds and rain, are lashing the region, with snowfall to 600m above sea level also forecast.
Mr Bush said the inclement weather made the search more gruelling but maintained his officers were used to working in such conditions.
"Doesn't help us, and I'm sure it doesn't help the person we're looking for," he said.
Superintendent Brett Kahan said the terrain was complex and dangerous, and it was difficult for searchers, even with their specialist resources, to move through quickly.
Anyone assisting Freeman has been urged to reconsider or risk prosecution.
"This person does not deserve to be aided in any way. If any person knows him or comes in contact with him, they need to encourage him to hand himself in," Mr Bush said.
Freeman, who has bush survival experience, was last seen wearing dark green tracksuit pants, a dark green rain jacket, brown Blundstone boots and reading glasses, police said.
He is believed to be a sovereign citizen, an ideology that rejects government authority and whose followers believe the rule of law doesn't apply to them, and who disassociate from society.
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