The brothers shot by police in Barnawartha North yesterday were radicalised before going to jail last year, NSW Corrective Services allege, as counterterrorism police say one of the men had been on their radar for at least two years.

Key points: Counterterrorism police wanted to speak to the men for a "routine" assessment about whether they posed a risk

Counterterrorism police wanted to speak to the men for a "routine" assessment about whether they posed a risk Police have said the older brother has been a person of interest for two years

Police have said the older brother has been a person of interest for two years Police emphasised yesterday's incident was not terrorism-related and there is no public threat

The pair, identified as Joshua Clavell, aged 30, and his 19-year-old brother, were injured during a confrontation in Barnawartha North near the New South Wales border.

It is understood they are related to Rodney Clavell, who was found dead after a stand-off with police in an Adelaide brothel in 2014.

The pair wielded a knife and a tomahawk and rammed the police car during the confrontation at the Richardsons Bend campsite, police said.

Victoria Police Chief Commissioner Graham Ashton earlier said the brothers had been exposed to ideologies in prison that were "problematic from a terrorism point of view".

A Corrective Services NSW (CSNSW) spokeswoman said the brothers had already been radicalised when they were charged with offences in August 2018.

"At that time, CSNSW … shared this information with other law enforcement agencies," the spokeswoman said.

They were released on February 4 after the charges were dealt with in a local court, which was the only time they had spent in CSNSW custody, she said.

Yesterday's confrontation was not terrorism-related and there was no ongoing public threat, according to police.

Albury Hospital said it was attending to a 30-year-old man in a serious but stable condition, while Melbourne's Alfred Hospital said it had a critical but stable patient.

Police said one officer was injured, but not seriously.

Intelligence raised concerns

At a press conference in Melbourne this morning, Assistant Commissioner Ross Guenther from Victoria Police's Counter Terrorism Command said the older brother was the focus of police inquiries.

He said the 30-year-old had been a person of interest to counterterrorism police for at least two years "because of the background of that individual".

He said both brothers had converted to a "very strict version of Islam" and that was the reason they wanted to assess whether the older brother posed any risk.

The 19-year-old had not been a person of interest, he said.

Speaking to ABC Radio Melbourne this morning, Mr Ashton said one of the men was "wanted on an old warrant" and counterterrorism police had been looking to speak to him.

Mr Ashton said there was no evidence the men were planning any kind of attack, but there was intelligence that suggested there was the "potential for radicalisation … because of their extensive criminal history".

"[There had been] some intelligence around them having ideologies that were problematic from a terrorism point of view," he said.

The site remained a crime scene this morning. ( ABC News )

"So [investigators] were trying to clarify where they were at, and having a conversation with them was what they were after," Mr Ashton said.

Last night, Acting Assistant Commissioner Clive Rust said police were "making routine inquiries in order to touch base with them, talk to them, assess them and make a judgement on whether or not they posed any risk".

'Strong hatred of police'

Assistant Commissioner Guenther alleged the older brother had "historical links to South Australia in relation to bikies", but that was not the focus of the investigation.

The older brother had "pretty strong hatred of police", he said, which was "pretty much evidenced" yesterday.

Assistant Commissioner Guenther said he had no evidence that the men had been radicalised in prison.

"I understand this goes back several years. There is a family of four brothers and I'd say out of that family three, perhaps four out of those are [converts] to Islam," he said.

Police said the men were likely to be charged over yesterday's alleged attack once their health had improved.

Homicide Squad detectives will investigate the shooting, with oversight from Professional Standards Command, as is standard protocol after a police shooting.