Governments around the world have failed in their war on drugs and fuelled a pandemic in HIV, a leading think tank has said.
The Global Commission on Drug Policy criticised nations for imprisoning non-violent drug users and for driving them away from public health services.
In its report, The War On Drugs And HIV/AIDS - How The Criminalisation Of Drug Use Fuels The Global Pandemic, the commission condemns "the remarkable failure of drug law enforcement policies" in cutting the world drug supply.
The global supply of illicit opiates, such as heroin, has risen by more than 380% in recent decades, the commission said.
The report's authors praise countries where "addiction is treated as a health issue" such as Australia, Portugal and Switzerland, where newly diagnosed HIV infections have been nearly eliminated among drug users.
But the authors criticised nations including the United States, China, Russia and Thailand, which have "ignored scientific evidence and resisted the implementation of evidence-based HIV prevention programmes - with devastating consequences," they said.
The commissioners also stressed the drug war's contribution to the growth of organised crime and spelt out how the drug war fuelled the HIV pandemic:
:: Fear of arrest driving drug users underground, away from HIV testing and HIV prevention services and into high-risk environments.
:: Restrictions on provision of sterile syringes to drug users result in increased syringe sharing.
:: Prohibitions or restrictions on opioid substitution therapy and other evidence-based treatment resulting in untreated addiction and avoidable HIV risk behaviour.
:: Deficient conditions and lack of HIV prevention measures in prison lead to HIV outbreaks among incarcerated drug
:: Disruptions of HIV antiretroviral therapy result in elevated HIV viral load (the concentration of the disease in blood) and subsequent HIV transmission and increased antiretroviral resistance.
:: Limited public funds are wasted on harmful and ineffective drug law enforcement efforts instead of being invested in proven HIV prevention strategies.
The report will be released at a press conference in London at midday.