It showed the levels of HIV prevalence among injecting drug users has remained below 2.1 per cent every year since the study began in 1995.

The study, conducted by the University of NSW's Kirby Institute, surveyed people who used government-run needle and syringe programs across the country.

The programs involve access to sterile needles and syringes as well as access to clinical services such as referrals to drug treatment programs.

The study's lead author, Jenny Iversen, said although the findings don't mean HIV has been eradicated from the injecting drug user community, levels in Australia are remaining low.

"It's not that there's zero transmission, but we don't have a situation where there's ongoing transmission to the point of having an outbreak," she said.

"In Australia we are able to contain the infection and put in place steps so it isn't being transferred to others."

The results make Australia a "unique" case, according to Dr Iversen, with other countries experiencing a HIV outbreak due to drug injection.

"They just had a situation recently [in the US] in Scotts County, Indiana, where a tiny community had a major outbreak," she said.

The success of needle and syringe programs around the country is largely credited for the low HIV-prevalence figures in the injecting drug user community.

Executive officer of the Australian Injecting and Illicit Drug Users League, Annie Madden, said the early implementation of the programs in the late '80s was a critical factor.

"It was important that the Australian government acted early, funding and implementing the needle and syringe programs right back at the beginning of HIV," she said.

"It's a really fundamental part at preventing HIV transmission."

Methamphetamine was identified as the most commonly used injecting drug in 2014, while the use of heroin has remained steady over the 20-year period.

The study found that risky injection behaviour such as re-using or sharing needles – the main way HIV is contracted among injecting drug users – is down from 20 years ago.

The amount of users who re-used needles declined from 33 per cent in 1997, to 21 per cent in 2014, while the number who shared them also decreased from 31 per cent in 1995 to 16 per cent in 2014.

Dr Iversen said the users who still share needles may be among the most vulnerable in the community.

"There's a certain proportion of the population that are homeless or have other socio-economic influences on their life that makes obtaining syringes and using them for a single injection a difficult task," she said.

The most common group among injecting drug users to contract HIV were gay men, with 30 per cent HIV positive in 2014.

The overall level of HIV in Australia has been rising since 1999, with the diagnosis rate being at its highest level in 20 years, according to the most recent figures.