The video says it shows a man named Won Young Youn, in a dark polo shirt, sitting casually at a table in Flushing, Queens. In his left hand he holds a recent purchase from an online auction, a small metal tablet that, he explains, is a plate that was used for printing currency in Korea during the tumultuous period before that country became a colony of imperial Japan
As to how the century-old artifact got from Seoul to an auction house in Michigan, Mr. Youn is frank: During the Korean War, an American Marine simply took it from the royal palace. He adds: “When I saw that, it really caught my attention.”
Now, Mr. Youn is in a federal detention center in Detroit, where he was taken after his arrest this month on charges of possessing and transporting stolen goods, felonies that each carry a maximum sentence of 10 years in prison.
The arrest came about as a result of a multiagency investigation that was aided by the South Korean government.
The arrest was also a result of Mr. Youn’s boasting. Though he received warnings, including one from the South Korean Embassy, that his purchase was illegal, he eagerly told Korean-language newspapers and radio and television stations of his acquisition.
The plate is perhaps the only survivor of a small number that were created in the 1890s, during a period of reform and the decline of the Korean monarchy, before the start of Japanese rule in 1910, according to Joshua Van Lieu, a professor of Korean history at LaGrange College in Georgia. Dr. Van Lieu, whose research on the plate’s significance was used in the investigation, added that given the plate’s rarity, “it would be priceless.”
Mr. Youn, 54, paid $35,000 for it in an April 2010 auction held by Midwest Auction Galleries, a company in Oxford, Mich.
The plate was among the items it was selling on behalf of a Michigan woman named Kathy Vogt; according to the criminal complaint, Ms. Vogt said she knew little about their provenance other than that they had been handed down by a relative who had been a Marine during the Korean War.
Reached by telephone, her husband, Robert Vogt, would not answer questions about the plate or the case. “The way things are, I would rather not discuss it right now,” he said.
Shortly before the 2010 sale, a State Department official as well as Jong Cheol Lee, the Korean Embassy’s counselor for legal affairs, warned the auction house that the plate was believed to have been looted, and that selling it would be a violation of the National Stolen Property Act, according to the criminal complaint.
A man who answered the telephone at Midwest Auctions last week said James Amato, the auction house’s owner, was not available to speak to a reporter. The man, who identified himself only as Jim, expressed surprise that Mr. Youn had been arrested.
No one associated with the auction house has been charged with a crime, said Gina Balaya, a spokeswoman for the Justice Department in Washington, who added that the investigation was continuing.
Mr. Youn, who lives in Fort Lee, N.J., bought the plate while using a friend’s computer in Flushing, the authorities said.
Mr. Lee said in an interview that when he called Mr. Youn after the sale and told him the item was stolen and should be returned, Mr. Youn said that as a Korean, he was proud to have reclaimed it. In the spate of coverage that ensued in the Korean media, Mr. Youn seemed to present himself as a sort of Indiana Jones figure, saving Korean artifacts from obscurity in the United States.
That posture did not make him hard to find. While Dr. Van Lieu was doing his research, he saw the video on YouTube of Mr. Youn sitting at the table in Flushing and holding the plate, according to the criminal complaint. Mr. Youn was arrested in Palisades Park, N.J., on Jan. 9. He is awaiting a detention hearing scheduled for this week.
Patrick J. McIlwain, a lawyer at Rha & Kim of Bayside, Queens, which represents Mr. Youn, said the firm was “committed to defending him.” He declined to comment further on the case.
The printing plate has been confiscated, a spokesman for United States Immigration and Customs Enforcement said. It is likely to be returned to South Korea. The situation was not what Mr. Lee, the embassy official, had hoped for. “The goal is not for a person of Korean origin to be convicted,” he said. “The goal is to retake a precious cultural asset.”
This article has been revised to reflect the following correction:
Correction: January 27, 2013
An earlier version of this article incorrectly characterized the period in which the plate was created. It was during a period of reform and the decline of the Korean monarchy, before the start of Japanese rule in 1910; not during a republic that briefly existed between the decline of the Korean monarchy and the start of Japanese rule in 1910.