Two brothers shot by police in Victoria are the sons of a man who was once deemed South Australia's most wanted and died during a siege in a brothel.
The siblings, aged 30 and 19, were shot near a camping ground at Barnawartha North near the NSW border on Wednesday afternoon after an attempted counter terror assessment turned violent.
Joshua Clavell remains stable in Albury Hospital with serious injuries, while his older brother is in a critical but stable condition after being flown to Melbourne's Alfred Hospital with abdominal injuries.
According to NewsCorp Australia, their father is Rodney Clavell, a former prison guard turned fugitive who shot himself during a 12-hour siege at an Adelaide brothel in 2014.
Mr Clavell was considered South Australia's most wanted man and was on the run from police for two weeks leading up to the siege, during which he kidnapped four women at the brothel.
Police on Thursday revealed the radicalised elder brother was on a terror watch list and had a long-standing hatred of police in the lead up to the shooting.
"The older one was the focus of our attention," Counter Terrorism Command Assistant Commissioner Ross Guenther told reporters in Melbourne.
"The person is known to Victoria Police, South Australian police and New South Wales police."
Mr Guenther said the 30-year-old had committed to a fundamentalist form of Islam several years ago before being sent to prison in NSW. He also had historical bikie links in South Australia.
Since his release from prison, he had been converting his three brothers to Islam and had gone to Bangladesh to get married.
When he returned to Australia he was considered a high threat, Mr Guenther added.
"The older brother has been a person of interest to us for at least two years," Mr Guenther said.
"He was on a list ... We have over 100 people that we monitor at various levels on that list, he was definitely one of those that was on the list.
"(He) has a history of a pretty strong hatred of police, which is long founded, which is pretty much evidenced in the way things played out."
The older brother posed a threat considered to be one below the "extreme" level, at which time the investigation is handed to the joint counter terrorism team.
"I haven't excluded this as a counter terrorism investigation on the face of it. I don't believe at this point it is," Mr Guenther said.
Police had attempted to contact the pair to assess the 30-year-old's threat level.
When the pair were found, they rammed the police car and lunged at the officers with a knife and a tomahawk.
Police had to quickly shoot the older brother. Attempts to negotiate with the younger man were unsuccessful and he was tasered before being shot.
Premier Daniel Andrews said Australia's terror alert level remained on probable.
"It is why we take these matters so, so seriously," he said.
"It is why there is a counter-terrorism command with a couple of hundred people working in it."
Homicide Squad detectives will investigate the shooting along with Professional Standards Command.