Prisoners being radicalised by 'hate preachers' in jail

IT IS Australia's harshest prison yet extremist preachers are expanding their influence under the noses of officers, surveillance and while enduring the brutal living conditions of the Supermax jail.

ABC's 7.30 reports counter-terrorism officials are warning that inmates are being won over to the Islamic State cause while inside the Supermax High Risk Management Centre in Goulburn in New South Wales.

Of the 41 prisoners dubbed the worst of the worst -- or "AA Extreme High Risk Restricted" -- 24 are considered a national security risk.

The make-up of prisoner numbers has been skewed due to a jump in terrorism-related arrests.

One of those who is winning others to his cause is Bilal Khazal, considered to be one of Australia's most notorious and influential terrorists.

He was a former confidant of Al-Qaeda mastermind Osama bin Laden, and had military training in Afghanistan.

Former radical preacher Junaid Thorne told the ABC he had become more influential since being in the Supermax prison, thanks to connections he made in the jail.

The Extreme High Risk prisoners are only allowed to associate with one other inmate, but ABC reports they were able to break the rules by shouting, passing messages and speaking in code.