POT smokers usually grow marijuana in their backyards or buy from their dealer mates. But now for many Australians, it's their postie delivering them the stuff from overseas.

The latest Customs figures show a boom in the number of cannabis detections in international mail at the border, with drug experts reporting that Aussies are turning to encrypted online stores to purchase what were once backyard drugs.

Dr Monica Barratt, a research fellow at the National Drug Research Institute, said they’re likely turning to online marketplaces like the so-called “Ebay of drugs”, The Silk Road website.

Drug dealers there are embracing sophisticated methods of packaging that are bypassing Customs and Quarantine drug detectors, she said, meaning packages of pot and psychoactive prescription drugs arrive in postboxes across the country.

Dr Barratt, who has been researching the internet and drug use for a decade, reported that commenters on the website said “‘Oh look, even I was fooled by the packaging. I received this package and I wasn’t even sure what it was until 10 minutes later when it all clicked’ ”.

The latest Customs annual report shows that detections at the border have surged from 412 in the year 2004/05 to 2692 in 2011/12, something a Customs spokesperson in part attributed to improved investment and efforts from the agency.

The big question: Why buy it online?

But the extent of hidden world weed web has surprised researchers, given that Australia has a strong domestic pot market and it’s so easy for Customs to detect by odour.

Dr Barratt said some of the reasons Australians are using the site include living in small towns where identification was easy and not knowing how to find dealers.

However, Professor Jan Copeland, the director of the National Cannabis Prevention and Information Centre at the University of NSW, said buying drugs online could be particularly dangerous for users.

“It’s just not worth the risk when they can grow it here,” she said.

More than a third of Australians have smoked weed, the 2010 National Household Drug Survey found, but some pot dealers don’t take too many precautions in selling their plants online.

"Weed convention"

Social media users are organising ‘weed parties’ in Perth on the public forum of Reddit.

Organisers claimed yesterday that the event had been a “rollicking success” in the past, but another commenter said: “I hope no one is stupid enough to show up for a weed convention announced over the Internet.”

Former policeman and cyber security consultant Nigel Phair told News.com.au that while websites like The Silk Road are encrypted, for the police “it’s technically possible to get around all these things.”

“It just takes resources and time,” he said.

In August this year, the National Drug and Alcohol Research Centre pointed out that the internet has become a major retailer for synthetic drugs like Miaow Miaow, even though the market is still in its infancy.

An Australia Post spokesperson said it was the responsibility of law enforcement, Customs and Quarantine to police drugs being sent in the post, not the post office.

But drug users be warned.

“I would also argue that doing things online leaves more footprints than you would in a real world transaction,” security expert Nigel Phair said.

Twitter: @drpiotrowski