WASHINGTON — The Chinese government systematically dismantled CIA spying operations in the country starting in 2010, killing or imprisoning more than a dozen sources over two years and crippling intelligence gathering there for years afterward.
Current and former US officials described the intelligence breach as one of the worst in decades. It set off a scramble in Washington’s intelligence and law enforcement agencies to contain the fallout, but investigators were bitterly divided over the cause.
Some were convinced that a mole within the CIA had betrayed the United States. Others believed that the Chinese had hacked the covert system the CIA used to communicate with its foreign sources. Years later, that debate remains unresolved.
But there was no disagreement about the damage. From the final weeks of 2010 through the end of 2012, according to former US officials, the Chinese killed at least a dozen of the CIA’s sources.
According to three of the officials, one was shot in front of his colleagues in the courtyard of a government building — a message to others who might have been working for the CIA.
Still others were put in jail. All told, the Chinese killed or imprisoned 18 to 20 of the CIA’s sources in China, according to two former senior US officials, unraveling a network that had taken years to build.
Assessing the fallout from an exposed spy operation can be difficult, but the episode was considered particularly damaging. The number of US assets lost in China, officials said, rivaled those lost in the Soviet Union and Russia during the betrayals of both Aldrich Ames and Robert Hanssen, formerly of the CIA and the FBI, who divulged intelligence operations to Moscow for years.
The previously unreported episode shows how successful the Chinese were in disrupting US spying efforts and stealing secrets years before a well-publicized breach in 2015 gave Beijing access to thousands of personnel records, including intelligence contractors.
The CIA considers spying in China one of its top priorities, but the country’s extensive security apparatus makes it exceptionally hard for Western spy services to develop sources there.
The unsettled nature of the China investigation demonstrates the difficulty of conducting counterespionage investigations into sophisticated spy services like those in Russia and China.
The CIA and the FBI both declined to comment. Ten current and former US officials described the investigation on the condition of anonymity because they did not want to be identified discussing the information.
The first signs of trouble emerged in 2010. At the time, the quality of the CIA’s information about the inner workings of the Chinese government was the best it had been for years, the result of recruiting sources deep inside the bureaucracy in Beijing, four former officials said.
But by early 2011, senior officers realized they had a problem. The FBI and the CIA opened a joint inquiry run by top counterintelligence officials at both agencies, and the CIA has been working to rebuild its network of informants.
China has been particularly aggressive in its espionage in recent years, beyond the breach of the Office of Personnel Management records in 2015, US officials said. Last year, an FBI employee pleaded guilty to acting as a Chinese agent for years, passing sensitive technology information to Beijing in exchange for cash, lavish hotel rooms during foreign travel and prostitutes.
In March, prosecutors announced the arrest of a longtime State Department employee, Candace Marie Claiborne, accused of lying to investigators about her contacts with Chinese officials. According to to the criminal complaint against Claiborne, who pleaded not guilty, Chinese agents wired cash into her bank account and showered her with gifts that included an iPhone, a laptop and tuition at a Chinese fashion school. In addition, according to the complaint, she received a fully furnished apartment and a stipend.