Accused Islamic State operative arrested in Australia

An accused Islamic State member has been arrested by counter-terrorism agents over allegations he instructed people how to plan and conduct mass-casualty attacks from his base in Australia.

The Melbourne man, who the Australian Federal Police alleges was a propagandist for the Islamic extremist terror group, is accused of sending about 10,000 documents, messages, images, videos and audio files relating to executions and torture.

The 65-year-old allegedly pledged allegiance to ISIS, which stands for the Islamic State of Iraq and Syria, and acted on its behalf without travelling to territory the terrorist organisation controlled during conflict in the Middle East.

The man was arrested at his Carlton home, in Melbourne's inner north, on Wednesday morning.

Counter-terror officers will also allege that the man shared information about avoiding detection from law enforcement, along with instructional guides on planning and conducting mass-casualty attacks.

He is expected to be charged with being a member of a terrorist organisation and violent extremist material offences.

It is believed more than 200 Australians have joined IS since 2012, some of the more than 50,000 fighters the group was thought to have attracted from overseas.

Having administered an area roughly the size of Great Britain across Syria and Iraq at its peak in 2014, IS has since been splintered by foreign adversaries into pockets of Nigeria, Mozambique and Mali.