Lee has been a suspect in a long-running probe to determine if a mole inside the US intelligence community had led to the deaths of a number of CIA assets in China, according to people with knowledge of the probe, which was first reported by the New York Times.
"The datebook contained handwritten information pertaining to, but not limited to, operational notes from asset meetings, operational meeting locations, operational phone numbers, true names of assets, and covert facilities", state court records cited by NBC News. There is also no explanation for why Lee is being charged so many years after he was found in possession of classified documents.
According to Federal authorities, Lee was arrested after landing in the USA from his home in Hong Kong where he now resides.
The case is being prosecuted by Assistant U.S. Attorney Neil Hammerstrom of the Eastern District of Virginia.
Lee's security clearance was terminated in 2007 when he left government service, according to the documents.
The documents in Lee's possession were photographed by Federal Bureau of Investigation agents on August 15, 2012, when Lee and his family arrived in Virginia from Hawaii and checked into a hotel in Fairfax.
In August 2012, prosecutors say Lee and his family relocated to northern Virginia from Hong Kong.
The small books were discovered inside Lee's luggage, sealed in a small clear plastic travel pack. He appeared in court Tuesday on one charge of unlawful retention of national defense information.
The address book "contained true names and phone numbers of assets and covert Central Intelligence Agency employees, as well as the addresses of Central Intelligence Agency facilities". It's unclear how the Federal Bureau of Investigation lured Lee back to the USA but officials say there have been several undercover attempts to incriminate him, and at least one confrontational interview during which he denied being a spy.
While the implication that Lee abetted Chinese counterintelligence efforts has been implied by sources who spoke to the Times and NBC, the arrest affidavit makes no mention of China or any other foreign nation receiving the information Lee held.
USA authorities have arrested a former Central Intelligence Agency (CIA) officer accused of disclosing top secret information to China.
A hunt for a "mole" in the agency led to one person, a "former operative" now living elsewhere in Asia, the Times said. At the time, the newspaper said, there was not enough evidence to arrest the suspected mole.