Police hunted through the night for the man, who they identified as Dezi Freeman, described by local media as a radicalised conspiracy theorist.

Officers set up a wide cordon around the crime scene, a rural property with a house and a bus in the small town of Porepunkah in the northeast of Victoria state.

“The suspect for this horrific event is still at large,” Victoria police chief commissioner Mike Bush told a news conference.

“I can assure everyone that we are pouring every resource into this search for this person. We must find him,” he added.

“He is very dangerous. He’s killed two police officers and injured a third.”

Police said they had spoken with the man’s partner and children to ensure they were safe, and to rule out the risk of any hostage situation.

Police said they believe Freeman has multiple “powerful” firearms.

Ten police had gone to the property on Tuesday morning to execute a search warrant when the gunfire broke out, the police chief said.

Police “did discharge shots in his direction” during the shootout, apparently without wounding the gunman, Bush said.

The shootout, which occurred “over minutes”, resulted in the deaths of a 59-year-old detective and a 35-year-old senior constable.

The wounded officer has been operated on and is “significantly damaged” but will recover, the police chief said.

While not revealing the cause for the original search warrant, he said the police team that descended on the property included local officers and members of the sexual offences and child investigation squad.

The manhunt is challenging, Bush said, explaining that Freeman is believed to understand “bushcraft” – surviving in nature – and “he will know that area better than us”.