Johannesburg's drug epidemic has exploded on to people's doorsteps.
Police and rehabilitation centres say they are battling a new enemy in the war against drugs as dealers move away from street sales to home delivery.
Gone are the days when a user had to risk going into dangerous areas such as Hillbrow or Yeoville to buy drugs.
Now, all it takes is a phone call or an SMS to a dealer, and within 15 minutes, any drug - be it heroin, cocaine, hashish or dagga - can be dropped off at a person's home, office or even at a restaurant.
In recent months, detectives have busted several mobile drug dealers, but they say they are fighting an uphill battle.
Police say it is difficult to arrest these dealers as they are constantly on the move.
Senior Superintendent Deven Naicker, the national head of narcotics, said the home delivery service had made the burgeoning drug epidemic harder to fight.
The trend was not confined to Joburg but was taking place all over the country.
"This has definitely made policing complicated as these guys are very clever. They never use the same car when delivering the drugs and they sometimes even hire metered cabs when doing drop-offs. This aspect of their transactions has made it complicated for detectives as these guys are always on the move," he said.
And, according to Professor Charles Parry, director of the Medical Research Council's (MRC) alcohol and drug abuse research unit, the home delivery service may also be contributing to the increased rate of addiction.
"This lowers the users' risk of getting caught as they now no longer have to go into, say, Hillbrow or a popular drug den. This could mean that their chance of becoming addicts increases. This concept makes perfect sense for both the dealer and user."
Statistics compiled by the MRC show that cocaine is increasingly becoming the drug of choice for many people, including black Africans.
Gauteng rehab centres say 11 percent of people treated were for cocaine and 8 percent for heroin.
The street price for pure cocaine is R350 a gram, or R250 if it is mixed with other ingredients, such as talcum powder. The going price for heroin is R50 a gram.
Rehab centres say the majority of patients have used the delivery service.
Dan Wolf, a psychologist and director of the Gap and First Step drug and alcohol recovery centres, said that last year he treated an 18-year-old girl who was buying drugs over the phone and sharing them with her 12-year-old sister.
"This poses a huge challenge as far as recovery goes, because a person's physical address has become contaminated. The home is usually a sanctuary, and what this does is make the home an extension of the drug den.
"What makes it even more scary is that vicious druglords know where their users stay, and if they are in debt, their family's lives are put at risk," Wolf said.
All a user has to do is call a dealer and tell him what drugs are wanted. The user would then be required to put the money in the postbox, and within a few minutes, the dealer will come by, take the envelope and insert another envelope in the postbox with drugs in it.
Naicker said this trend was started a few years ago by West African drug syndicates.
"Not just anybody can pick up the phone and call a guy for drugs. A person would have to be referred to the dealer before he makes a delivery. They are very wary who they deliver to," he said.
The Star has spoken to several former addicts who have used the service. They said dealers were aware the police might be watching them, and to avoid detection they would never pick up a call from a landline and would answer only if their number appeared on the dealer's cellphone.
They never speak for more than 30 seconds and never drop off drugs twice in a day.
"They are very scared of being spotted. My guy would tell me that I should take a bit more drugs and pay him another time as he didn't want to come to my place twice in one day because he might be spotted."
Dean Francis, a former addict who is now a counsellor at a recovery centre, said the use of the drug delivery service had grown as cellphones became more popular.
"Most of the people who get treatment know their dealer and have used the service. It gives them a sense of security knowing that they don't have to leave home to get drugs," he said.