Australians are choosing meth as their drug of choice, according to wastewater analysis which found national consumption of the substance is increasing.
The Australian Criminal Intelligence Commission's (ACIC) National Wastewater Drug Monitoring Program measures the demand for a range of illicit and legal drugs across 57 capital city and regional wastewater sites.
This accounts for about 56 per cent of the Australian population.
The analysis, which was released on Wednesday, found meth use increased around the country between December and April.
ACIC chief executive Michael Phelan says the results are due to a mix of normal market forces, supply-side decisions by serious and organised crime groups and drug busts by authorities.
He pointed to decisions by European organised crime groups transitioning from manufacturing ecstasy to meth, as one reason for the change.
The removal of COVID-19 barriers also led to an increase in supplies.
The consumption of ecstasy, oxycodone and fentanyl fell to record lows.
"The decreases in consumption are likely related to supply issues," Mr Phelan said.
Heroin use remained stable in the capital cities while consumption increased in the regions.
Melbourne ranked first when it came to meth consumption, while South Australia came out on top for regional methamphetamine use.
Melbourne and regional NSW topped the list when it came to heroin use while cocaine was the first drug of choice in Sydney and NSW regions.
The new data comes as a UNSW study found a large increase in national cocaine-related deaths in the past decade.
The study, led by Shane Darke, found 884 cocaine-related deaths between 2000 and 2021.
However, records show 398 deaths in the past five years, accounting for about 45 per cent of total deaths.
Professor Darke attributed the increase to more widespread use of cocaine, including a spike in deaths among people with no history of drug use.
"Twenty years ago, 90 per cent of cocaine deaths had a history of substance use problems, now that figure is much lower at 50 per cent," he said.
Mr Phelan says understanding drug use at a population level is important to effectively allocate resources and strategies.
"This is critical in addressing drug use in Australia," he said.
