KABUL , Afghanistan ( CNN ) -- Afghanistan 's reputation as the world 's leading narcotics supplier is well-known , but in a squalid ruin in Kabul , the country hides a darker secret -- a huge home grown drug addiction problem now on the brink of fueling an HIV/AIDS epidemic . Junkies smoking heroin can get high for $ 4 . Here junkies lie in their own filth , wasted limbs poking out of blood-spattered clothing as they blank out the abject misery of their surroundings . In one room , a veritable narcotics bazaar offers pills and drug paraphernalia -- with hits retailing at less than $ 4 . One user claims he has been an addict for 22 years , although it is difficult to talk to any of the dazed and ragged occupants of the drug rooms . The atmosphere is edgy and -- as thick clouds of burning opium fill the air -- dizzyingly toxic . The Kabul den is just the tip of the iceberg in a country awash with narcotics . The government estimates the number of addicts in Afghanistan could be as many as five percent of its 25 million people . Watch Nic Robertson 's report from the 'house of hopelessness ' » . And though nascent efforts are being made to tackle the problem , chronic funding shortfalls have prompted the United Nations to warn that drug use will escalate , potentially driving an HIV/AIDS crisis as junkies move from smoking to high risk needle-sharing . Afghanistan has always been a major narcotics supplier -- responsible for 95 percent of the world 's heroin -- although this was scaled back under the rule of the Taliban , which outlawed poppy cultivation and imposed strict penalties for drug users . Since 2001 , when the extremist regime was ousted by a U.S.-led invasion that installed President Hamid Karzai , production has doubled . And for many in the country still mired in poverty and conflict , these cheap drugs offer a tempting escape . The last United Nations survey of Afghanistan 's drug problem four years ago estimated the country 's addicts to number about 200,000 . According to Afghan Counter Narcotics Minister Khodaidad , the figure is now far greater . `` More than 1.2 million people in Afghanistan are addicts . It 's a very huge number and every year it increases , '' he told CNN . Khodaidad says the Afghan government is largely powerless to control the production of opium while Taliban extremists , who now control and draw funding from drug crops , control cultivation areas despite major international military efforts to push them back . `` We did very little due to weakness of governors , due to insurgents , due to pressure of terrorism in the area , '' he added . `` We do n't have sufficient law enforcement agencies -- the police , the border security force , and other special forces to control this area -- so it will take time . '' But , says Jean-Luc Lemahieu , head of the UN 's Office on Drugs and Crime ( UNODC ) in Kabul , time is something Afghanistan does not have . As intravenous drug use takes hold , raising the prospect of needle sharing , he says HIV/AIDS will follow quickly . `` The little data we have at the moment are very alarming , '' he told CNN . `` They tell us that we should not wait longer and if not , this country will be saddled with another burden it just can not afford . `` I think it is already happening today . We have seen , now , a few HIV/AIDS cases . Hopefully we can contain the problem , although it is unlikely given the problems with the health structures . '' The U.N. has begun a program to detox users willing to get off drugs in Afghanistan . A renovated warehouse in Kabul offers hope to 100 addicts in the biggest facility of its kind in the country . Watch Robertson go inside the detox clinic » . In the center 's clean , bare rooms , shaven-headed junkies tremble under blankets as they go through the agonizing cold turkey of weaning their ravaged bodies off drug dependency . Therapy sessions also help motivate them to kick their deadly habit . `` Here we deal with the problem from a humanitarian perspective , not from an addiction perspective , to save lives , '' says Jehan Zeb Khan , UNODC program manager . But says Khan , with what little funding there is now dwindling fast , the salvation offered to these lucky few may be short lived -- they will be forced back out on the streets , where more opium dens will flourish , bringing yet more misery for Afghanistan .
Government officials say 1.2 million Afghans are now addicted to drugs . United Nations says growing drug use could lead to HIV/AIDS crisis . Afghan President Hamid Karzai has said he will not sign the treaty because it doesn't address his country's opium problem.