Washington: A United States defence contractor and former state department security officer was arrested by American counterintelligence officials on Thursday and charged with spying for China.
The justice department said Kevin Mallory of Leesburg, Virginia had sold classified documents to Chinese intelligence agents on trips to Shanghai in March and April.
He could face up to life in prison if found guilty.
The source and content of the documents in question was not divulged, but was characterised as "defence information" for which he received $25,000.
"Your object is to gain information, and my object is to be paid," he told the Chinese in a 5 May message, according to an indictment.
Mallory, 60, is a fluent Mandarin speaker who had served in the United States army, then as a special agent for the security service of the state department, before becoming a contractor to various government agencies.
Up until 2012 he had a "top secret" clearance level in positions in China, Taiwan, Iraq and Washington.
The Washington Post said Mallory had worked for the CIA.
The indictment says he made contact via social media in February with a Chinese "recruiter" who helped arrange a trip the next month to Shanghai to meet intelligence officials.
They were working under the guise of scientists with the Shanghai Academy of Social Sciences, according to the indictment.
They trained him in using a special communication device which, when examined by investigators, showed Mallory planning to hand over more documents.
Mallory was charged with delivering defence information to a foreign government and with making false statements to Federal Bureau of Investigation (FBI) agents.
Updated Date: Jun 23, 2017 10:01 AM