The man, who identified himself as Karl Fredrik Mattsson in a press conference on Wednesday, made eight counterfeit coins in his so-called “experiment”.
Instead of the usual “Carl XVI Gustaf Sveriges Konung” ('Carl XVI Gustaf Sweden's King'), the text written around the image of the King's head on the counterfeit coins read “Vår horkarl till Kung”, which translates roughly into English as “Our whorer of a King”.
Mattsson explained that he never put the coins into circulation; rather, he gave them to friends and acquaintances who shared their “findings” with Swedish media at the time.
It was Mattsson's mother, in fact, who reported the first finding in June from up in Piteå in far northern Sweden.
The professional work of the counterfeiter impressed and baffled experts.
Meanwhile, the amateur artist, who works as a copywriter, wouldn't explain to the gathered media why he made the coins or what they mean.
“I won't explain why. I don't think that it's my responsibility as an amateur artist to explain art for someone,” he said at the press conference, according to the Aftonbladet newspaper, adding that he was prepared to face the music over his king-mocking coins, if need be.
“I am ready to be charged if the king wants to charge me,” Mattsson said.
The coins' royal insult is an apparent reference to the King's rumoured infidelities detailed in a tell-all biography of the king published in late 2010.
The book, entitled “Carl XVI Gustaf - Den motvillige monarken” (‘Carl XVI Gustaf - The reluctant monarch'), included a rare and detailed look into the King's private life, including details of love affairs, wild parties with Swedish models, and connections to the underworld.
A couple of samples of the coins are currently on display at the National Museum of Economy in Stockholm.