A former C.I.A. officer suspected by investigators of helping China dismantle United States spying operations and identify informants has been arrested.
The arrest of the former officer, Jerry Chun Shing Lee, 53, capped an intense F.B.I. inquiry that began around 2012, two years after the C.I.A. began losing its informants in China.
FBI agents discovered he had handwritten notes containing the "true names" and "phone numbers" of assets, covert CIA employees and CIA facilities.
Some intelligence officials believed that a mole inside the C.I.A. was exposing its roster of informants. Others thought that the Chinese government had hacked the C.I.A.’s covert communications used to talk to foreign sources of information.
Mr. Lee, who left the C.I.A. in 2007, has been living in Hong Kong and working for a well-known auction house. He was apprehended at Kennedy Airport in New York and charged in federal court in Northern Virginia with the unlawful retention of national defense information.