Peter Dutton has called for a crackdown on the use of encrypted messaging apps after two police officers and a local man were shot dead in an ambush at a remote Queensland property last week.
The Opposition Leader warned Parliament last week that encrypted messaging apps were hosting "anti-authoritarian lunacy" and needed to be monitored by authorities.
Members of the Train family - former school principal Nathaniel Train, his brother Gareth and sister-in-law Stacey – shot and killed police who visited their property to investigate a missing person report.
Constables Matthew Arnold and Rachel McCrow were killed along with neighbour Alan Dare, who was shot when he went to help.
Police are investigating the Train brothers' online activities and checking for their involvement in extremist conspiracy groups and forums.
Dutton went on Nine Radio last week to urge friends and families of people ‘falling down conspiratorial rabbit holes’ to advise authorities before events took a tragic turn.
"There are some sick individuals out there and the internet's made it possible for them to spread their lies and their hatred, and so it is difficult for authorities to pick that up," he said.
"The parallel obviously is with young people who are being indoctrinated online ... they spend hours and hours and hours reading this information and information is deliberately posted, knowing that will influence people in a negative way."
Dutton’s warnings about the use of encrypted messaging services ignored the fact that, according to investigators, the Train family posted their conspiracy theories on internet forums rather than via secure software.
Dutton is the latest in a list of politicians calling for measures to counter extremism online.
Labor MP Peter Khalil, who chairs federal parliament's intelligence and security committee, recently told AAP that “online echo chambers” were making pathways to radicalisation possible.
"The pipeline towards extremism needs disrupting at its source not just at the pointy end of the spear where violent attacks are imminent," he said.
"By anticipating the increased raft of national security challenges ... we can take decisive action and counter-measures to improve our resilience."
Attorney-General Mark Dreyfus said Queensland police needed time to complete their investigation of last week’s tragedy without speculation or interference.
"Right now, three families are grieving and the Queensland Police are conducting an investigation into these horrific murders," he told journalists.