Alaa Adam Atwani is accused of supporting the Islamic State in Iraq in 2014 by providing "Sony Vegas video-editing software" to a relative who had travelled to the conflict zone.

Australian Federal Police (AFP) alleged Mr Atwani's relative was working for the "media unit" of the group.

AFP assistant commissioner Ian McCartney said the arrest had helped protect national security.

"We will allege that the support this man provided was tangible and would directly assist a terrorist organisation with its objectives," he said.

According to court documents, police alleged the offence occurred in Sydney between late October and early November in 2014.

Read more: ABC News (Australia)