"This case is like nothing we have ever seen on Australian soil," AFP Assistant Commissioner Neil Gaughan said. The attempted transactions related to sale of missile guidance systems and other missile componentry, and to the sale of coal, to third parties in Indonesia and Vietnam. Prime Minister Malcolm Turnbull said he had been briefed by AFP commissioner Andrew Colvin on the "very, very serious matter". He warned anyone thinking of assisting the rogue state that "the AFP will find you". "North Korea is a dangerous, reckless, criminal regime threatening the peace of the region, it supports itself by breaching UN sanctions, not simply by selling commodities like coal and other goods, but also by selling weapons, by selling drugs, by engaging in cyber crime," Mr Turnbull said.

"It is vitally important that all nations work relentlessly to enforce those sanctions because the more economic pressure that can be brought on North Korea, the sooner that regime will be brought to its senses. "The charges that are being laid are of the gravest nature, so I'll say no more about the facts of the case, obviously it will be dealt with in court." Mr Choi has been charged with six offences, two under the Weapons of Mass Destruction (Prevention of Proliferation) Act 1995. The other four are under legislation enforcing UN and Australian sanctions against North Korea. Mr Gaughan stressed that there had been no risk to the Australian public and that no weapons or missile componentry had been imported into Australia. "This is black market 101," he said.

"We are alleging that all the activity occurred offshore, and was purely another attempt for this man to trade goods and services as a way to raise revenue for the government of North Korea," he said. "This was his goal. His actions were all around trying to raise revenue for the government of North Korea." He said it was believed the man had been in contact with high-ranking North Korean officials but gave no other details of how or when the man was recruited as a North Korean economic agent. "I know these charges sound alarming. Let me be clear we are not suggesting there are any weapons or missile componentry that ever came to Australian soil, nor that we believed that we identified any immediate threat to the Australian community." The allegation in relation to the missile componentry is that the man participated in discussions about the provision of the componentry, which assists in the guidance of ballistic missiles, from North Korea to other entities.

"This man was acting as a loyal agent for North Korea. "The evidence suggests there had been contact with high-ranking officials in North Korea," he said. However, Assistant Commissioner Gaughan said there was no evidence, and in fact there was evidence to the contrary, that any other foreign government officials were involved in the matter. Rather, the charges related to "people trying to use the blackmarket as a way to get things they shouldn't get hold of and then also to receive revenue back in return. "That's the same with the coal, and the oil and everything else we will be alleging, and also some gemstones and the like as well, it is all about making money for the North Korean government," he said.

Mr Choi was arrested following the execution of search warrants in Sydney on Saturday. The matter came before before Parramatta bail court on Sunday. He did not apply for bail and did not appear in the courtroom. Assistant Commissioner Gaughan said investigations were ongoing, and that the AFP was working closely with intelligence agencies and overseas law enforcement partners. The man's activities were being investigated back as far as 2008, and it was possible other charges would be laid. He added: "There are relatives in Australia that we are currently speaking to and there are ongoing investigations in relation to those particular people." Police will allege that the man provided services to a "weapons of mass destruction program" and discussed the sale of ballistic missile technology. They will further allege those discussions included the setting up of a "ballistic missile production facility", the supply of missile construction plans and the provision of North Korean technical specialists for training others outside North Korea. But Mr Gaughan would not name the potential partner to the missile componentry transaction.

"There are ongoing investigations in relation to that," he said. In relation to the size of the transactions, or potential transactions, Assistant Commissioner Gaughan said: "There are some financial records that indicate well over half a million dollar transfer that we are aware of but we estimate that if these trades were successful we would be talking tens of millions of dollars." The charges are the first under the Weapons of Mass Destruction (Prevention of Proliferation) Act.