"This man was a loyal agent of North Korea, who believed he was acting to serve some higher patriotic objective", Gaughan said, according to Seven Network Australia.
"This man was a loyal agent of North Korea, who believed he was acting to serve some higher patriotic objective", said Australian Federal Police Assistant Commissioner Neil Gaughan, adding that the case was "like nothing we have ever seen on Australian soil".
The man who has been charged with brokering black market deals involving missile components for North Korea worked as a hospital cleaner in Sydney by day while allegedly sending encrypted messages to Pyongyang and his business partners by night.
The sales would violate Australian and United Nations sanctions.
"This may have been as good as it gets for Pyongyang, in order to fulfil that backroom economic function, whether it's over the table or under the table", he said.
However, the North has shown little interest in talks until it has the ability to hit the U.S. mainland with a nuclear-tipped missile, which many experts say it has yet to prove.
According to the Australian Federal Police, the suspect was arranging the sale of weapons of mass destruction parts and planned to transfer coal to Vietnam and Indonesia.
"I know these charges sound alarming, but let me be clear", commissioner Gaughan said.
What do you think of PUBG on Xbox One?
I mean, in some ways I can't blame them given that the Xbox One's library is more starved of good games than the PlayStation 4. So we would definitely get to see this game for the PS4 console, but again there is no any confirmation on this as of now.
Chan was arrested at his home in suburban Sydney Saturday.
"This case is like nothing we have ever seen on Australian soil", he said.
"This is a very important arrest, the charges laid are of the greatest nature", Prime Minister Malcolm Turnbull told reporters in Sydney.
Choi was a naturalized Australian citizen who had lived in the country for more than 30 years, police said.
"North Korea's threats only strengthen our resolve to find a peaceful solution to the rising tensions on the Korean Peninsula caused entirely by North Korea's illegal, threatening and provocative behaviour", she 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. He added: "There are relatives in Australia that we are now speaking to and there are ongoing investigations in relation to those particular people".
The man was charged on two counts under a law against proliferation of weapons of mass destruction, police said on Sunday. 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.
"There are ongoing investigations in relation to that", he said.