The Western Australian Aboriginal affairs minister, Ben Wyatt, has dismissed suggestions from WA police that they need a directive from cabinet to act on a report showing that police issue three times as many traffic fines to Indigenous drivers.

An internal police briefing note, published by Guardian Australia, showed Aboriginal drivers receive 3.2 times more fines issued during traffic stops than non-Aboriginal drivers, but slightly fewer than non-Aboriginal drivers in infringements issued by traffic cameras.

The briefing note said an analysis of five years of traffic infringement data in WA showed a “clear ethnic disparity” in traffic fines issued by police, which contributed to a cycle of unpaid fines and was “likely to lead to further police attention”.

WA police said they had not done anything in response to the briefing note, dated 13 February 2019, because reducing Aboriginal incarceration was a priority for Mark McGowan’s government and therefore deciding on actions that could reduce Indigenous incarceration was a matter for cabinet.

But Wyatt said that “police can, and do, act on the findings of internal briefing notes, particularly around operational matters”.

The minister said he was not personally aware of the briefing note. “However, I understand the broad issues captured in the note were raised with the cross-agency officers’ group responsible for progressing the Aboriginal wellbeing target,” he said. “It will be considered as part of the group’s policy development going forward.”

Wyatt said he had been “impressed” with the police commissioner Chris Dawson’s efforts to date to improve the relationship between police and Aboriginal people.

The briefing note states that an analysis of traffic infringements between 2010 and 2014 showed a “clear ethnic disparity” in police-initiated traffic stops.

“These differences are large enough to suggest an uncomfortable distinction between automated camera and police-initiated traffic enforcement, with this distinction heavily correlated with Aboriginality,” the briefing note said. “If the automated cameras are assumed to objectively reflect any actual differences in on-the-road behaviour, our data suggest that Aboriginal and non-Aborignal drivers are equally prone to breaking traffic laws.”

The trend was largely unchanged in data from January 2017 to mid-2018, when Aboriginal drivers still received more than three times as many penalty units from police stops than non-Aboriginal drivers, and roughly the same number from cameras.

Dawson told Perth radio station 6PR on Thursday that there were “lessons to be learned” from the report, but did not respond directly to questions about whether he believed WA Police targeted Aboriginal people. He pointed at the final lines of the report, which said the analysis “by no means provide[s] conclusive evidence that deliberate bias exists.”

The report’s author, Dr Geoffrey Barnes, told Guardian Australia that comment, which preceded a call for more research, was a standard caveat on all scientific research.

Dawson told 6PR the report “does cast doubt and we are continuing to work around it.” He confirmed that the evidence-based policing unit, which produced the report, had been greatly reduced.

“I’ve pared it right back … I have other priorities,” he said. “I’m not saying it had no utility [but] I think it was over-emphasised for a moment in time.”

Nerita Waight, co-chair of the National Aboriginal and Torres Strait Islander Legal Service, said the “over-policing and profiling of Aboriginal people in Western Australia has been an ongoing problem for community.”

“Unfortunately, the inappropriate use of police discretion in these situations is not just a Western Australian problem, it is a problem across the entire country,” she said.

“Because police have broad discretionary powers they act as the gatekeepers on who enters the criminal legal system and how …

“Being imprisoned, even if it’s for a short amount of time, puts the lives of Aboriginal and Torres Strait Islander people at risk of being drawn into the quicksand of the criminal legal system, which can be deadly for them.”

The McGowan government last year introduced legislation to abolish the practice of jailing people for unpaid fines. That practice only applied to court fines, not traffic infringements, unless the infringement was dealt with before the court.

The legislation, which is yet to pass parliament, would also allow authorities to garnish the salary of a person who has unpaid fines until the debt is cleared.

It was prompted by the 2014 death in custody of the Yamatji woman Ms Dhu.

Monique Hurley, a senior lawyer at the Human Rights Law Centre, said racially motivated over-policing could cause “enormous harm”.

“This data shows clearly that WA police have a serious racism problem,” Hurley said. “For WA police and the WA government to just sit on their hands in the face of this stark injustice is inexcusable. A good government would take immediate action.”