German police have arrested a 34-year-old Australian man for his alleged involvement in running DarkMarket – a dark web marketplace selling drugs and malware that Europol described as the "world's largest".

The man was picked up near the Danish-German border last weekend before law enforcement shut down the DarkMarket site on Monday.

Europol claimed DarkMarket had seen over 500,000 users and facilitated the transaction of over 4,650 bitcoin and 12,800 monero during its operation worth in excess of $220 million.

Police seized over 20 servers in Moldova and Ukraine as part of an international operation that included the involvement of the Australian Federal Police (AFP).

Investigators will use information gathered from this operation to try and find more buyers, sellers, and moderators running dark web marketplaces.

Splash page of the DarkMarket site after being seized by police. Source: Europol

In a statement to Information Age, an AFP spokesperson congratulated its German counterparts for its arrest of the suspected DarkMarket operator.

"This result is significant with impacts around the world on thousands of Dark Market vendors and users, demonstrating how global law enforcement efforts can have great success in identifying and targeting dark net marketplace hierarchy," the AFP said.

"The dark web increasingly hosts large-scale, complex and anonymous platforms and services which are frequently used to facilitate the most serious of crimes, including child sexual abuse, drugs and firearms trafficking, extremist content and sale of stolen identification documents.

"Our message is clear, if Australians are considering using a dark net marketplace to conceal criminal activity, your anonymity is not guaranteed and you are not outside the reach of law enforcement."

Anonymous Tor journalist going by the name noticed DarkMarket claimed to be "the first local marketplace run exclusively by women". also said DarkMarket was built on Eckmar's marketplace script – a ready-made encrypted marketplace coded in PHP which is "infamous for insecurities and half-baked features".

Dread users comb through the post history of /u/darkmarket to see where he went wrong. Source: Dread

One user of the dark web forum Dread looked through the posting history of /u/darkmarket – a user affiliated with the DarkMarket service – and pointed out clues that could identify the user as Australian.

"Aussie ex-pat, living in EU, drug background, tech background, crypto background," the user said.

"When you can blend in with all of the possible people, why do you choose to narrow yourself down?"