Users of the dark internet have shed light on their illegal trades on a growing online black market, which is helping more and more Australians to buy drugs and weapons.

A number of sites compete for the drug dollar online, selling drugs and sending them through the post to customers across the globe.

Customs spokesman Matt Wardell says the illegal trade has been linked to a spike in drug and weapons seizures at Australian mail centres.

"Certainly over the past 12 months, last financial year for example, we noticed a jump of more than 40 per cent in the number of small seizures made at mail centres across the country," he told 7.30.

"That's obviously got a lot to do with the increase in online trade.

"There's no question that it's become a more attractive way for people to try and import prohibited goods into the country - be they guns, be they drugs."

The Silk Road website - an eBay for drugs where encryption software allows vendors to be anonymously rated - is giving authorities a particular headache.

Bill, whose name has been changed, is a vendor on Silk Road who posts drugs to customers in Australia.

As a seller on the site he has access to some buyer information, and he says business Down Under is good.

"Australian traffic has double, tripled, quadrupled. There's more buyers, you can see them on the forums, you can see them on the posts," he said.

"Not only that, but in recent months there's been an American traffic explosion and that led to the site actually going down for a certain amount of time."

Nobody knows the identity or location of the founder of Silk Road, who goes under the pseudonym The Dread Pirate Roberts.

To protect its illegal trade, the site uses complex masking software and money exchanges.

Users have to download an encryption network, and the only money allowed is Bitcoin - an online currency that also hides purchasers' identities.

Computer expert Chris McDonald is not a Silk Road user but has studied the technology behind it and believes it is unbeatable.

"We're talking about tens of thousands, if not millions of years to break into these algorithms," he said.

"So for a small piece of data we have the traditional problem where if you spend more effort trying to break into an encrypted piece of data, then by the time you've successfully broken into the data, the data itself has no value."

'Easy money'

There has been a 40 per cent jump in the number of small seizures made at mail centres. ( AAP/Australian Federal Police )

But Customs and the Australian Federal Police are warning that sites like Silk Road only lead to jail.

Mr Wardell says there have been a number of successful prosecutions but could not say how many, saying there are too many agencies involved.

"It is a very big risk if you try to bring this stuff into the country," he said.

"There's a very big risk Customs and Border Protection will seize it at the border, you'll lose your money, you'll lose the goods and you may go to jail."

But Perth man Ryan West, 20, says that is not the case.

Mr West works as a storeman driving a forklift, but previously made a living buying MDMA - the main ingredient in ecstasy - from his bedroom.

He then sold it onto friends and acquaintances, who picked up the drugs from his house.

"Extremely profitable - $300 investment into $2,500 in a day," he said.

"It was very easy to resell. I was buying because it's very scarce here and everywhere around the world it's quite cheap."

His world of drugs and easy money came crashing down in August when authorities raided his house.

He was convicted of four charges, including intent to supply a prohibited drug, and placed on an intensive supervision order.

'Too easy'

Mr West says he was only caught because he was dealing drugs out of his house.

He says other users on Silk Road, who post drugs to their customers, run little risk of being caught.

"I was extravagant, I didn't care if I got caught, I wasn't covering my trails at all," he said.

"I was happy to get caught really because I was stuck in there anyway, I was stuck in dealing, it was too easy to do and too hard to get out of.

"Authorities will not be able to stop this. They can slow it down, but there's always going to be drugs in the mail one way or another."

That sentiment is echoed by Bill, who is not worried by the attention from Customs and believes Silk Road is the future of drug dealing.

"If Silk Road was shut down, people would simply transfer over to a new network," he said.

Mr Wardell says the anonymous nature of the dark internet brings bigger dangers than being arrested.

"You have no quality control when you're buying things from an online anonymous market place," he said.

"So not only are you breaking the law, but you're arguably taking a big risk with your own health.

"The argument about whether this is safer or more convenient doesn't really wash. It's still illegal and it's a big risk."

Despite that, there continues to be a demand for drugs and there are plenty of sellers ready to meet it.