FBI Employee Arrested for Allegedly Acting as Secret Chinese Agent

— -- An FBI employee has been arrested in New York for allegedly lying about secret work for Chinese businessmen and government officials, according to charging documents filed in the case unsealed today.

Kun Shan "Joey" Chun pleaded guilty in federal court today to one count of illegally acting as an agent of a foreign government. He had been working for the FBI's New York field office as an electronics technician since 1997. He was quietly arrested in March after his own office sent an undercover agent to meet with him and record their conversations, according to the charging documents.

Since at least 2006, according to the FBI, Chun and some of his family members maintained close ties with at least one person he "understood to be affiliated with the Chinese government" and multiple businessmen tied to Kolion, a manufacturer of printer products in China. These associates demanded Chun advise them on technology matters and conduct research for them, in exchange for regular payments and sometimes prostitutes, according to a criminal complaint filed in federal court in New York City.

As recently as last summer, Chun allegedly met with some of these Chinese associates in Europe. A month earlier, the FBI sent in an undercover agent, who told Chun he was a Chinese-born U.S. citizen working as a private contractor for the Department of Defense.

Chun allegedly told the undercover agent he wanted everyone to develop a "consulting" relationship, and Chun allegedly expressed a desire to pass sensitive U.S. government information to those associates, including people associated with the Chinese government.

After secretly being arrested in March, Chun confessed to most of the allegations against him and admitted to taking steps to collect sensitive FBI information based on tasking from a Chinese government official, according to federal authorities.

"Kun Shan Chun violated our nation's trust by exploiting his official U.S. government position to provide restricted and sensitive FBI information to the Chinese government," Assistant Attorney General John Carlin, the head of the Justice Department's national security division, said in a statement.

Chun was initially charged under seal with several federal offenses, most accusing him of lying to federal authorities and failing to disclose his relationships with certain Chinese nationals during a 2012 background investigation for a top security clearance.

In October 2015, he acknowledged in a recorded conversation with the undercover agent that he had broken the law, saying, "I lied. I reported certain people [but] not everybody."

Illegally acting as an agent of a foreign government, to which Chun pleaded guilty today, carries a maximum sentence of 10 years in prison.

Chun was born in China in 1969 and became a U.S. citizen in 1985, according to court documents.

ABC News' Josh Margolin contributed to this report.