Police have seized Dutch online bazaar Utopia, a website similar to the infamous Silk Road website for trading illegal goods, and arrested five suspects, the Dutch public prosecutor says.
Buyers could access the site using the Tor platform, which provides anonymity on the internet, and purchase drugs including ecstasy and cocaine as well as guns and stolen credit cards.
Purchases could be made using the virtual Bitcoin currency, of which police seized 900, worth between 400,000 euros and 600,000 euros ($A599,135-$A904,250).
"Police infiltrated and bought several items of drugs and firearms," the public prosecutor said in a statement.
Undercover Dutch police were also contacted and paid to carry out a contract killing, the statement said.
Internet news website DeepDotWeb published screen grabs of some of the products that had been available on Utopia, including "Blue Nintendo" ecstasy pills at 207 euros for 50.
Police opened their investigation last year into Utopia and similar website Black Market Reloaded (BMR), which "left the internet after receiving a lot of visitors at the end of last year", the prosecutor said.
The increase in visitors to BMR came after US authorities in October shut down the Silk Road website, known as "the drugs eBay".
Police seized Utopia's Germany-based servers and arrested a person there. Dutch authorities hope he will be extradited to the Netherlands.
The other four suspects, aged 29 to 46, were detained in the Netherlands.
Utopia was accessible using Tor (originally an acronym for The Onion Router), an anti-censorship navigator that affords web anonymity by shifting the apparent identity of a user's computer around the world by changing its IP address.
US authorities in October arrested 29-year-old Ross William Ulbricht for allegedly running the Silk Road online black market bazaar.
He pleaded not guilty on February 7 to charges including money laundering and drug smuggling.
