Silk Road, an illegal online marketplace that used Bitcoins to sell drugs and guns, has been shut down by US law enforcement agencies.

Its alleged mastermind, William Ulbricht, a 29 year old advanced chemistry graduate, has been arrested and the website closed.

Silk Road came to notoriety in 2011 and allowed anonymous dealers and buyers to trade narcotics, weapons, and even hit men for hire.

It was possibly the world’s best known facilitator of Bitcoin, a peer to peer anonymous currency first developed in 2009.

The FBI says Silk Road witnessed up to US$1.3 billion in sales in Bitcoin, with $80 million in commissions.

It worked by creating anonymous accounts for sellers and buyers, in a not entirely dissimilar model to popular marketplace, Ebay.

Buyers, who ranged from seasoned criminals through to petty drug users, would generally have goods mailed to a private post box.

Inside Retail understands Silk Road’s sellers had a small but significant market in Australia.

It is unclear if the FBI will be targeting buyers or sellers of illegal goods now the alleged mastermind’s website has been seized.

Since his Wednesday arrest, Ulbricht has been described by his parents as a “good person” but has also been linked to wishing death on others.