Law enforcement agencies around the world took part in Operation Hyperion, a co-ordinated effort to target traders of illegal drugs over the internet.
From October 22 to 28, agencies focused on packages coming through mail centres, and then tracked these back to buyers and sellers.
Among the illegal drugs found were small amounts of cocaine, methamphetamine, heroin, alpha PVP, LSD, ecstasy and cannabis seeds.
National high tech crime group manager Kelly Knight said the local operation had resulted in six arrests and 66 formal warnings, and had identified almost 300 people involved in the illegal drug trade.
"The clear message for people who think they can use the internet to buy illegal drugs and get away with it is that they can't,'' she said.
"These sites are not top secret. Police can view them, and together with Customs we can track packages down to addresses and individuals.''
One person faces 13 charges for importing ecstasy, LSD and cannabis.
Police have also charged a 22-year-old man in connection with the creation of site VicUnderworld, which police said was no longer operating.
In addition to New Zealand Police and Customs, Operation Hyperion involved Europol, Australian Federal Police, United States Immigration, Customs and Homeland Security, the FBI and other international law enforcement agencies.
The dark web is an online black market that requires specific software, configurations or authorisation to access.
In April, an Illicit Drug Monitoring System study showed that encrypted websites were becoming increasingly popular among New Zealanders who were seeking to buy and sell drugs.
