Accused of 'empire building': Minister Peter Dutton. Credit:Andrew Meares

"Now homeland security or home affairs has been spoken about here over a long period of time. Different governments and ministers have looked at it. The Prime Minister's made comment on it the other day but I'm just not aware of the process beyond that and if there's consideration, it's an issue for others," Mr Dutton told Sydney radio station 2GB.

"But from my perspective, we work well with the agencies and we want to make sure that there are no silos, we want to make sure that we're sharing all the intelligence and information because it's part of the reason that we can thwart these terrorist threats before they are realised."

Mr Dutton said, as in the case of accused "fake doctor" Shyam Acharya, "you necessarily want to make sure that you're getting access to all of the information that whatever government department holds" on anyone being investigated by authorities. He said "we live in a very different age" to 10 or 20 years ago and it was difficult to predict security threats over the near future.

"So we've just got to make sure that we've got a modern system that is going to deal with people crossing our borders, sharing intelligence with law enforcement agencies and intel bodies and the rest of it. We've got the best people in the world and my sense, my only requirement, is that we continue that world's best practice," he said.