A former CIA officer has been arrested in the US on charges of unlawful retention of classified information.
Jerry Chun Shing Lee, a naturalised US citizen, was held at New York's JFK airport on Monday, the US justice department said.
He worked for the CIA between 1994 and 2007, when he left for Hong Kong.
The case is thought to be linked to an FBI investigation, which began in 2012, into the crippling of the CIA's spy operation in China.
In the two years before, some 20 informants had been killed or jailed - one of the most disastrous failures of US intelligence in recent years.
Mr Lee, also known as Zhen Cheng Li, served in the US Army from 1982-86, say court documents.
He began his CIA career in 1994 as a case officer. He was given top secret clearance and signed several non-disclosure agreements.
When Mr Lee left the CIA in 2007, "those who knew him said he left the agency disgruntled after his career plateaued", reported the New York Times.
Mr Lee remained in Hong Kong and only returned to America in 2012 - according to one report, lured by a fake job offer, reports, BBC.