They were aware Joshua had moved into Victoria just weeks ago after he was released from remand prison in NSW in February this year. Victorian investigators travelled up to the border town of Albury-Wodonga to meet their NSW counterparts to assess the risk that Joshua posed, senior police said on Thursday. Seemingly by chance, counter terrorism detectives were at a petrol station at Barnawartha, west of Wodonga, when they spotted the brothers filling up their car. The brothers recognised the detectives were police officers and took off, ramming a police car before local officers tracked the brothers to the Richardson Bend nature reserve on the banks of the Murray River. Police at the campground in Barnawartha North. Credit:Mark Jesser/Border Mail

Attempts to subdue the brothers failed, police said, before they lunged at the officers - two of them from the small police station of Rutherglen - with a knife and a tomahawk. The older brother allegedly charged police first and was shot. Police tried to negotiate with the teenager for a number of minutes and used a Taser and capsicum spray before he also allegedly lunged at officers and was shot. Joshua is in a stable condition in hospital in Albury and Joel is fighting for his life in The Alfred hospital in Melbourne. School friends of Joel have described how he would sometimes vanish from South Australia without a word to live interstate with his sister. "It was one day at school and vanished the next. No one knew what happened him," said a Zac Butler, his friend from Moonta Area School on the Yorke Peninsula.

The violent confrontation was captured on the officers' body cameras. Police are now investigating whether the brothers had taken up residence at the camping ground in an attempt to "get off the grid", Victorian counter terrorism boss Ross Guenther said. "Perhaps they felt they were under too much spotlight," he said. Rodney Clavell. Credit:South Australia Police Mr Guenther said the older Clavell brother had previously travelled to Bangladesh to marry before returning to Australia.

The men are from a family of four brothers and police believe Joshua had indoctrinated two of his three brothers into the radical form of Islam, Mr Guenther said. "The older brother made a commitment to this form of Islam several years ago, he sought to impact that thinking onto his brothers. That's occurred over a time period of several years," Mr Guenther said. "That older individual in our terminology would be at the threat level that is very high. "We have over 100 people that we monitor at various levels. He was definitely one of those on that list." Their father was considered South Australia's most wanted person at the time he took four women hostage in the Adelaide brothel in 2014. The 12-hour siege shut down part of Adelaide's CBD.

Joshua, who has previous links to a South Australian bikie gang and a known hatred of police, has not been charged with any terrorism offences previously, Mr Guenther said. His most recent arrest was in Sydney in August last year where he was charged with robbery, larceny and intimidation offences. "At that time, Corrective Services NSW identified that [he] had already been radicalised and shared this information with other law enforcement agencies," a spokeswoman said. The robbery charge was later dropped, and he was found guilty on the other charges. He appeared in Burwood Local Court in February where he was released without any conviction recorded. "This was the only time the [he was] in CSNSW custody," the spokeswoman said.