Victoria Police know when they bust into the family homes of young, allegedly radicalised Muslim men, that they might alienate the community on whose help they rely to identify potential terrorists.
But Assistant Commissioner Stephen Fontana, who is in charge of Victoria Police's anti-terror response, told The Age they had little choice sometimes but to act strongly.
"We often have to make these decisions – they're about high-risk operations and they're not made lightly. Sometimes we can't tell the community why we've made that decision," Mr Fontana said.
"There's always a risk that some actions will cause angst within the community, but sometimes the risks are real, and we've got to act accordingly."
The Victorian assistant commissioner for counter-terrorism co-ordination would not refer to specific operations, some of which are before the courts, but confirmed that information from the community had been critical in a recent spate of Melbourne terror arrests.
However, he said the flow of information was reliant on good relations between the Muslim community and police which, after the death of Numan Haider and the recent raids, had grown strained.
"The stakes are pretty high when you're dealing with these young individuals, and that makes our job hard, but the bottom line is we've been engaging with the community for many years. Yes, we do go through some difficult times, but overall the relationship is strong."
Mr Fontana said police had caught some of the recent alleged plots late, and acknowledged: "We've been lucky."
"The pace has sped up considerably, but fortunately, we do have good sources."
However, Mr Fontana complained that growing anti-Islamic sentiment in the community – represented by anti-halal food groups and the hard-line Reclaim rallies – was making the police job more difficult.
"Any sort of groups like that, whatever their intentions are, can create tension and intolerance, and that intolerance can lead to racism, and it can further marginalise young people ... and it's inappropriate ... People really need to think about what cause they're going in for."
Asked if these sentiments were alienating young Muslim men and becoming something of a "push factor" in Islamic State recruitment, Mr Fontana said: "It has a potential to."
The April 18 raids, which police allege disrupted an Anzac Day stabbing and shooting spree, were initiated after British police found details on an encryted messaging application in the phone of a 14-year-old British schoolboy. The boy had been arrested on an "unrelated criminal matter".
Another recent arrest in a northern suburb that cannot be named was made in haste as the result of a late tip-off from the community.
Mr Fontana would not comment on whether he believed the police luck would hold.
"The reality is, there's a lot of people that have been travelling that we don't know about; they're probably in the conflict zone [in Syria and Iraq], and the risk is always there that someone won't be on our agenda."
At least one formal complaint has been made about alleged police brutality during the April 18 raids, and The Age understands that a number of others are likely.
Mr Fontana said they would be thoroughly investigated, with oversight both internally and by the Independent Broad-based Anti-corruption Commission.
