Police have returned to a rural property where two officers were ambushed and executed in cold blood, as their all-out land and air search continues.

Porepunkah, about 300km northeast of Melbourne, remains in lockdown as police pursue the accused gunman Dezi Freeman - also known as Desmond Filby - after he fled into bushland.

Detective Leading Senior Constable Neal Thompson, 59, and Senior Constable Vadim De Waart, 35, were killed while attempting to serve a search warrant at the property on the outskirts of the town on Tuesday morning.

Another wounded officer is expected to recover after undergoing surgery.

Detective Leading Senior Constable Neal Thompson and Senior Constable Vadim De Waart were killed. – AAP

"This devastating loss of Neal and Vadim has struck at the heart of Victoria Police, the broader policing family and the community of Porepunkah," Chief Commissioner Mike Bush said.

"In the coming days, weeks and months, we will all grieve this loss and deeply miss our colleagues and friends who have paid the ultimate sacrifice in the line of duty."

The weather in Victoria's high country continues to deteriorate as the search focuses back on the property.

Victorian Police at the scene. – AAP

Several police cars, some with NSW plates, were seen driving to the blocked-off property.

Two helicopters were searching the alpine region, with one hovering on top of the property before leaving just after 2pm.

A no-fly zone, spanning about 7.5km, for all aircraft and drones has been granted by the aviation bureau and will run until at least 11.30pm on August 29.

Police confirmed there has still been no sighting of Freeman in a statement at 2pm on Wednesday.

Suspect Dezi Freeman in a 2018 TV interview. – AAP

They released a photo of the suspect, who was described as Caucasian, 183cm tall, medium build, short dark hair and brown eyes.

He was last seen wearing dark green tracksuit pants, a dark green rain jacket, brown Blundstone boots and reading glasses.

Glen Siede, whose family runs a caravan park close to property, said he knew the "bush like the back of his hand".

"There's a lot of mine shafts and dugouts up in the bush," he told AAP.

"They (police) have got some challenges and I feel sorry for them."

Marty Robinson, who has known Freeman for about 30 years, suggested the fugitive was highly intelligent.

He couldn't say for certain but believes Freeman is bunkered down in bushland.

"He will survive out there," he told AAP. "He's the modern-day Ned Kelly."

Victorian Police Chief Commissioner Mike Bush speaks to the media. – AAP

Bush conceded Freeman knew the area better than police and warned he could be carrying multiple high-powered guns.

"He understands bush craft well," he told reporters in Melbourne.

Police are confident he has not crossed the NSW border but their state counterparts are on high alert.

Police at the scene of a shooting in Victoria's High Country. – AAP

Freeman was known to police and a risk assessment was completed before 10 officers, local police and others from the sexual offences and child investigation team, executed the warrant.

The surviving officers hunkered down and returned fire but he managed to evade police.

Freeman's partner and children went to a police station on Tuesday night and have since been interviewed.

A police vantage point has been established at Feathertop Winery.

A police helicopter involved in the manhunt. – AAP

A police text message told residents to stay indoors, with the local school closed on Wednesday after being locked down following the shootings.

Porepunkah, known for its vineyards and scenic vistas, is a gateway to Victoria’s alpine tourist region. Public buildings and the nearby airfield were closed and the local school of just over 100 students was in lockdown for hours before students were allowed to go home.

“Be vigilant, keep yourselves safe,” Bush urged residents. “Please don’t go outside if you don’t need to.”

Bush admitted that the suspect's knowledge of outdoor survival skills posed a “challenge” to authorities. The whereabouts of Freeman’s wife and two children were initially unknown, but they had visited a police station and spoken to officers late on Tuesday night, Bush said.

Freeman is believed to be a sovereign citizen, an ideology that questions government authority and whose followers believe the rule of law doesn't apply to them and who disassociate from society.

Chief Commissioner Mike Bush speaks to the media on Wednesday. – AAP

Prime Minister Anthony Albanese said Australia's security intelligence had previously warned about "far-right extremism" involving so-called sovereign citizens.

"The fact this ideology of not seeing themselves being subject to our laws and our society ... is of real concern," Albanese told ABC television.

He also drew similarities between the incident and another in Wieambilla in 2022, when two Queensland officers conducting a welfare check were shot dead by people who identified as sovereign citizens.

Victorian Premier Jacinta Allan described Freeman as a criminal and said the law applied to everyone.

A large contingent of police at a stage area at Feathertop Winery in Porepunkah. – AAP

Shooting deaths in Australia are rare

Members of Victoria’s police union were stricken by a “shocking and eerie feeling of dread", said Police Association Victoria Secretary Wayne Gatt.

“Police stations have fallen silent in Victoria when we were first notified.”

Shooting deaths in Australia are rare. A 1996 massacre in the Tasmanian town of Port Arthur, where a lone gunman killed 35 people, prompted the government to drastically tighten gun laws and made it much more difficult for Australians to acquire firearms.

The bushland hunt for accused cop killer

What is Dezi Freeman accused of doing?

• Freeman shot dead two officers, a 59-year-old detective and a 35-year-old senior constable, at a rural property in Porepunkah, about 300km northeast of Melbourne.
• A third officer was wounded and is recovering in Melbourne's Alfred hospital after undergoing surgery.
• The trio and seven other officers were there to serve a search warrant related to a specialist investigation team.
• The other officers had to "hunker down" and await police back-up and are believed to have returned fire.
• Freeman fled into dense bushland and remained on the run as of Wednesday.
• There is no hostage situation, with his partner and children going to a police station on Tuesday night.

Who is Dezi Freeman?

• A 56-year-old local known for having views consistent with the sovereign citizen movement.
• He and his family were featured in a 2018 segment on Nine's A Current Affair about a dispute with neighbours at their then Mount Buffalo property.
• Freeman, who also goes by Filby, tried to arrest a magistrate during a hearing in Wangaratta Magistrates Court in 2019.
• He told a podcast at the time he was a photographer from Myrtleford in the state's northeast and made a series of "pseudolaw" statements.
• Freeman was arrested outside Myrtleford Magistrates Court in 2021 after the failed private prosecution of then-state premier Daniel Andrews for treason.
• His appeal against a two-year driving ban, in which he represented himself and expressed hatred of police, was thrown out in 2024.

Where is he?

• Police have been unable to pinpoint Freeman's whereabouts, with no confirmed sighting.
• A massive air and ground search has been mobilised across a wide area of thick bushland.
• Police say Freeman is an experienced bushman and concede he knows the area better.
• He is believed to be armed with multiple powerful guns.
• Locals have been told to stay home and avoid the general area of Porepunkah.
• There is no evidence he has crossed the border into NSW, police say.
• NSW Police have been briefed and are on the lookout.