Loading "The idea that [Islamic] community leaders would have information but withhold it from the police or intelligence agencies is unacceptable. "We're best to be honest about the problem so we can address it, because otherwise more Australians will lose their lives." Mr Dutton took aim at Muslim Labor MP and counter-terrorism expert Anne Aly, who was critical of Mr Morrison's blunt remarks about extremist Islam following Friday's attack. The West Australian MP had accused Mr Morrison of using divisive language because he was "politically desperate", and said the PM should "read a book" about religious extremism.

Home Affairs Minister Peter Dutton said it was "unacceptable" for Muslim leaders to withhold information from police. Credit:AAP Mr Dutton accused Ms Aly of seeking to "deny that there's a problem" with Islamic fundamentalism. He also said it proved Labor "doesn't have the ability, frankly, to put in place the laws, to put in place the resolve to keep our borders secure and country safe". Labor leader Bill Shorten also condemned violent Islamic extremism at the weekend, saying it had become "prevalent in a very small part of a radicalised minority". Police have described Shire Ali - who killed beloved Melbourne restaurateur Sisto Malaspina and left the city in shock - as a lone-actor terrorist who was known to authorities but was not known to be planning an attack. Sources close to the family indicated Shire Ali had mental health and substance abuse issues.

On Saturday, Mr Morrison decried radical Islam as "the greatest threat of religious extremism in this country". Loading Rodger Shanahan, a terrorism analyst at the Lowy Institute, said Mr Morrison was clearly "correct" and should not have his remarks misinterpreted or re-purposed for political gain. "People won’t listen to the nuance," he told Fairfax Media. "They’ll go off on their own tangent, sometimes because they didn’t listen to what he said, or in [Ms] Aly's case because she’s a politician from the opposition and she wants to make a political point.

"It’s a sensitive topic, but you can either talk around it or you can talk at it with all the nuances that it requires – which I think is what [Mr] Morrison did." Mr Dutton said there were "always lessons to learn" from such attacks, and named the government's failed crackdown on citizenship applications as something the Coalition should again pursue. He also stressed the need to pass a bill currently before a parliamentary inquiry that would assist police to bust encrypted communications, The Assistance and Access Bill 2018. Mr Dutton confirmed Shire Ali had been questioned by ASIO and had his passport cancelled in 2015. He said early investigations suggested Shire Ali was inspired by Islamic State rather than affiliated with the terrorist group. Flowers outside Pellegrini's Espresso Bar on Bourke Street, whose proprietor Sisto Malaspina was killed by Shire Ali. Credit:Timna Jacks It was close to impossible for authorities to foil terrorists who used readily available materials such as a car and a kitchen knife, Mr Dutton said, and thus they relied on tip-offs from the public.