"Most police forces simply do not collect or differentiate this type of offence, they do not identify it as a unique offence. An assault is an assault." Loading Mr Kaldas said cracking down on the issue included dealing with complaints from multicultural communities that police did not take hate crimes seriously enough. "Nazi graffiti on a synagogue or racist comments on a mosque wound communities deeply and, if allowed to go unchecked, can be the first steps someone takes towards acts like the NZ attacks," he wrote. Victorian Chief Commissioner Graham Ashton has confirmed that police had stepped up their surveillance of “alt-right” figures since the attack on Friday.

Loading Replay Replay video Play video Play video And Mr Shorten said Mr Kaldas' idea made perfect sense which may not even require formal legislation to put in place. A centralised database and a common definition of hate crimes across all jurisdictions would help deal with the growing threat posed by right-wing extremists. Loading "It needs to be accessible and we would need a common definition of hate crime. We know these people want to find loopholes so they can escape scrutiny so we have to make sure it works. Prime Minister Scott Morrison said given the "horrific" events in Christchurch, there was always something that could be learnt.

"Our agencies and our government will do whatever is necessary to keep Australians safe by acting on the expert advice we receive," he said. But as investigators in Australia and New Zealand attempt to piece together Tarrant's itinerate lifestyle and radical views, counter-terrorism experts warn of the difficulties in tracking down self-radicalised members of the "alt-right". Deakin University Professor Greg Barton said intelligence agencies were acutely aware of the threat, and that right-wing extremists were responsible for every fatal terrorist attack in the US last year - more than 50 deaths. The police are in the situation where they're not wanting to cry wolf all the time ... but of course there are wolves in the forest. Deakin University professor Greg Barton However, Professor Barton said "alt-right groups" were harder to monitor than other terrorist organisations such as Islamic State and al-Qaeda, whose supporters operated within well-defined networks that were well known to law enforcement agencies.

"Generally speaking you're not getting the intelligence advantage of seeing a lot of chatter between dozens of individuals," he said. Professor Barton said it was also virtually impossible to distinguish between the online rantings of neo-Nazis and those harbouring serious intentions to carry out terrorism. "What we do know is that he (Tarrant) was posting on Facebook and Twitter and being a nuisance, but the problem is that there's thousands of guys posting similar things. "The police are in the situation where they're not wanting to cry wolf all the time ... but of course there are wolves in the forest and it's a question of knowing who is worth paying attention to," Professor Barton said. Professor Barton said Tarrant had been inspired by Norwegian mass murder Anders Behring Breivik, who was also a "classic loner" and "vaingloriously concerned about his reputation with his online community".

Mr Kaldas cited the United States where the Federal Bureau of Investigation produces an annual report on hate crimes. It started as a federal piece of legislation in the 1990s. Its latest report showed a 17 per cent lift in hate crimes across the US. Mr Kaldas said while it was not a perfect system, the FBI was collecting information from 15,000 police agencies which provided a reasonably accurate insight into hate crime activity. "We have eight police forces in Australia, and have not managed this. If you cannot measure it, you cannot deal with it effectively," he wrote. Former NSW deputy police commissioner Nick Kaldas says a national database of hate crimes would help identify potential hardcore criminals much earlier Credit:Nic Walker "And, by the way, the latest report from the FBI highlighted that for the past three years hate crimes were rising, significantly in some categories. Other reporting from the US has indicated that identified hate groups are at record high levels."

Over the weekend, Prime Minister Jacinda Ardern conceded that Tarrant was "not on the radar" of security agencies in Australia or New Zealand. Dr Allan Orr, a counter terrorism and insurgency specialist, defended the performance of intelligence agencies in both countries. "As terrorism goes, this is a text-book example and could not have been foreseen. This guy never talked politics at the gym, he never talked politics at the gun range, he kept a closed loop. "If he was on the radar, we wouldn't be living in a democracy, sometimes they get through and you get hit," Dr Orr said. Victorian Chief Commissioner Graham Ashton confirmed that police had stepped up their surveillance of “alt-right” figures since the attack on Friday.