A much purer version of heroin, and consequently more dangerous, is haunting the Australian capital of Canberra.
Purer heroin means people are more likely to underestimate the effects and take more than they might usually, points out Directions ACT executive director Carol Mead.
''At the moment the white heroin that's on the streets is about 80-85per cent pure, and that's a real problem.
''If they have very pure heroin, they're getting more bang for their buck.
''That's very often the reason they overdose, because they have more than they bargain for,'' Ms.Mead said.
A former user said the quality of speed and crystal methylamphetamine had slumped, turning people towards heroin.
But he said heroin purer than 60-70 per cent was still rare, and ''you'd be lucky to find the right people''.
Still, the Australian Capital Territory's Ambulance Service was called out to 127 suspected drug overdoses in 2008.
If Ms Mead's estimate of 80-85 per cent purity is accurate, that is still significantly more potent than much of what the Australian Federal Police has been seizing at the country's borders.
An AFP spokeswoman told Louis Andrews of The Canberra Times that by the time today's heroin hit the streets, it was generally about 20 per cent pure.
''This means that 1kg of heroin seized at the Australian border is cut to 3.5kg of heroin for use on the streets.''
Canberra's supply was not exclusively pure, Ms Mead said.
''There's also some heroin available which is fairly oily,'' she said. ''They often call it hillbilly heroin or brown heroin, and that tends to come from the Middle East, Afghanistan and places like that.''
The Australian National Council on Drugs said this week that the country was at risk of increased quantities of Afghani heroin because of the conflict there and the breakdown of law and order in South West Asia.
Robert Ali, Chairman of the Council's Asia-Pacific Committee, said in a statement that 90% of the world's heroin was now coming straight out of Afghanistan.
"After declines in the use of heroin in Australia from 2001 and declines in the number of overdoses, there are new risks for Australia.
"....the rise in heroin in the region has the clear potential to lead to an increase in Australia and hence the number of injecting drug users as well as issues that are associated with that including the increased risk of HIV infection."
The warning comes as the Council points out that:
Global opium production has now reached record levels... globally opium production has increased by 102% in the period 1998-2007.
Opium cultivation in South East Asia has increased by 22% after 6 years in decline. Most of this was through a 29% increase in Myanmar (Burma) to 27,700 hectares.
51% of the world's heroin users are in Asia reflecting the fact that opium consumption is still widespread across the Asian region.
80% of global opiate seizures in 2006 were made in Asia... 69% of them were in South West Asia.
The number border detections of heroin in 2006/07 was the highest on record.
In 2006/07 the weight of heroin seizures in Australia increased by 192%. In essence, the amount of heroin seized in Australian in 2006/07 doubled from the previous year.
While heroin from Afghanistan is often smoked, of great concern are reports indicating it was also being produced in a more processed form to allow easier injection.
Since 2001 there has been a dramatic decline in the number of heroin overdose deaths in Australia.
Associate Professor Ali said "This welcome decline in deaths in Australia reflects law enforcement efforts in reducing supply, increased investment and availability of treatment and innovative peer-based education work by users themselves. However, the number of fatalities still exceeds an average of one person a day and this means a tremendous amount of trauma for families and friends everyday across Australia."
He also warned it was vital that Australia provides assistance to countries in the region dealing with a HIV epidemic. He says as Australia has been spared from the HIV epidemic amongst injecting drug users through effective strategies such as needle and syringe and methadone programs.
Australia now has an obligation to provide assistance to other countries in the region, Prof. Ali stressed.