A former CIA officer has pleaded guilty to conspiring to pass U.S. defense and intelligence secrets to China, the Justice Department said on Wednesday, in the third such case in less than a year.

Jerry Chun Shing Lee, 54, was arrested in January 2018, suspected of having provided information on a CIA network of informants that was brought down by China between 2010 and 2012. Lee pleaded guilty before a U.S. District Court judge in the Eastern District of Virginia to conspiring to provide national defense information to China, the Justice Department said in a statement. Lee, a former CIA case officer, left the Central Intelligence Agency in 2007 and moved to Hong Kong.

In March, a former U.S. Defense Intelligence Agency (DIA) officer, Ron Rockwell Hansen, pleaded guilty attempting to transmit classified information to China and receiving hundreds of thousands of dollars while acting as an agent for Beijing. Last June, another former CIA case officer, Kevin Mallory, was convicted on espionage charges for passing classified documents to China. This week, FBI Director Christopher Wray said China posed the biggest threat to the United States when it came to economic espionage. Last month, the Justice Department said a former engineer and a Chinese businessman had been charged with economic espionage and conspiring to steal trade secrets from General Electric in a scheme for which the Chinese government provided "financial and other support."