A former Central Intelligence Agency (CIA) officer suspected of compromising American spies in China, has been arrested after authorities discovered notebooks filled with the details of informants working.
Jerry Chun Shing Lee, also known as Zhen Cheng Li, is suspected of aiding the collapse of the US spy operations in China, which saw dozens of informants jailed or killed from 2010 onwards.
Mr Lee, a 53-year-old naturalized US citizen, was detained at New York’s JFK airport on Monday and charged with retaining highly classified information.
Mr Lee, who now lives in Hong Kong, worked for the CIA between 1994 and 2007 and had top-level security clearance.
It is reported that several members of the intelligence community suspected a mole within the agency at the time.
The New York Times reported last year that starting in 2010, to the end of 2012, the Chinese killed "at least a dozen" sources the CIA had inside China and imprisoned six or more others.
In 2012, five years after he had left his post, FBI agents conducted a court-authorized search of a Hawaii hotel room where Mr Lee was on a layover from Hong Kong to the US.
According to one report, Mr Lee had been lured back to the US by a fake job offer.
FBI agents found and photographed two small notebooks that contained handwritten lists of the real names and contact numbers of China-based American assets.
According to a court affidavit, the books held notes of varying degrees of classification, but at least some information was top-secret and could, if revealed, “cause exceptionally grave damage to the national security of the United States”.
It is unclear why Mr Lee was not arrested on his arrival in the United States during his 2012 visit.
He was allowed to return to Hong Kong without incident, only to be arrested on his arrival in the US this week.
Charges of the unlawful retention of national defence information have been filed against Mr Lee, who faces a maximum penalty of 10 years in prison, according to the Justice Department Statement.
The accused has so far made no public comment on the case.