Only 21 people have been convicted under hate crime laws in Australia, despite state police forces recording thousands of offences connected to discrimination.

Key points: Only 21 people have ever been convicted of a hate crime in Australia

Only 21 people have ever been convicted of a hate crime in Australia Victorian police flagged 4,257 incidents during a four-year period as being linked to prejudice

Victorian police flagged 4,257 incidents during a four-year period as being linked to prejudice An US hate crime expert says Australian police had their "heads in the sand" when he met with them in 2016

Internal Victorian police data obtained by Background Briefing shows on average, there are approximately three offences flagged as motivated by prejudice each day.

Despite this, only three people have ever been convicted under Victoria's Racial and Religious Tolerance Act.

In NSW, no-one has been convicted of threatening or inciting violence on the basis of prejudice since records began in 1994. The same goes for South Australia, which has had a Racial Vilification Act since 1996.

In Tasmania, the Northern Territory and the ACT, racial vilification is not a criminal offence.

Australian police don't take hate crimes seriously: US expert

Within the law enforcement community, there has been debate over whether enough is being done about hate crimes.

To address the problem, a secretive conference was held in Sydney in March 2016 to discuss the threat posed by hate groups.

In attendance were the Australian Federal Police, ASIO, state and territory police departments, and New Zealand law enforcement officials.

Matt Browning, a former undercover officer with the Arizona police who specialises in tracking far-right gang activity, was invited by NSW Police to share intelligence at the conference.

"I basically said that you have people that are here and Sydney-based who are travelling around the world financing and funding white supremacist organisations," he said.

"So why aren't we watching them, why aren't we going after these people?"

Mr Browning said his briefing earned a cold reception.

NSW Police said officers were trained to identify bias crimes. ( ABC News: Dan Cox )

"Everybody was sticking their heads in the sand and it was because nobody really wanted to admit the fact that an Australian could be a member of a hate group," he said.

A number of those in attendance, he said, reacted with comments to the effect of "it's not that bad here" and "this isn't America, that stuff only happens in America".

NSW Police personnel who were interviewed in a recently published Sydney University study expressed similar concerns to Mr Browning.

"The biggest issue with NSW Police is we're run by old white men," one anonymous officer said. "I think the direction in this organisation has always been to shut the minorities up.

"Nothing changes until somebody dies … until the day a white supremacist walks into a mosque."

His statement was made two years before the Christchurch massacre.

How Australian police deal with hate crime

The former race discrimination commissioner Tim Soutphommasane said if police did not record and act on common cases of racial vilification and abuse, it made it harder to prevent major hate crimes.

"Hate speech leads to political violence if you allow it to escalate," he said.

"It's absolutely necessary for our society to send a message that it's not in any way acceptable and should be held accountable under the law."

Professor Gail Mason, a criminologist at the University of Sydney, said when hate crimes were reported police officers were often not adequately trained to record them.

Professor Gail Mason from the University of Sydney gained rare access to the inner workings of the Bias Crime Unit within NSW Police. ( ABC News: John Stewart )

"It is going to be difficult for the average frontline police officer to have the knowledge to actually be able to ask why a crime was committed and to then recognise, 'well perhaps this is a crime that's motivated by prejudice and I need to record it as such'," she said.

Professor Mason authored the research into NSW Bias Crimes Unit, which quoted 10 anonymous police personnel discussing the response of police towards hate crimes.

"Some officers are really good at finding reasons why [an event] wasn't a bias crime," one participant told Professor Mason.

"You kind of have to be naive to think that the reason we're not jumping up and down saying bias crime is happening here is not political," another member of police staff said.

"There's definitely pressure … at levels much higher than mine to not present NSW … as a dangerous place to be."

The Bias Crimes Unit of NSW Police had its staff reduced from four officers to one earlier this year.

A NSW Police spokeswoman said in a statement the unit was supported by the Counter Terrorism and Special Tactics Command intelligence unit — and every officer had training and understanding of bias crime.

Professor Mason said even when prejudice was flagged as a factor, police and prosecutors often preferred to pursue charges that were easier to prove in court.

Offences like stalking and wilful damage do not require prosecutors to prove the motivation of the perpetrator and result in greater penalties.

But this can lead to a statistical black hole, according to Mr Soutphommasane.

"What gets measured gets done," he said.

"If you don't know just how prevalent hate crime is in our society it becomes very easy then to dismiss it as just a theoretical threat."