Alexander Yuk Ching Ma, 71, was arrested in August 2020 after admitting to an undercover FBI agent that he sold US secrets to China.
Ma, a naturalised US citizen born in Hong Kong, worked for the CIA from 1982 to 1989. He went on to work for the FBI later in his career.
Part of his plea agreement states that he must co-operate with prosecutors “for the rest of his life, including by submitting to debriefings by US government agencies”.
The plea deal requires him to submit to polygraph tests during those debriefings, according to the Associated Press news agency.
At a sentencing hearing on Wednesday, lawyers for the US government told the court that he has been co-operative, and has already taken part in “multiple interview sessions with government agents”.
Officials say Ma collaborated with a relative, who was also a CIA agent, to supply secrets to intelligence officers employed by the Shanghai State Security Bureau.
One meeting in Hong Kong was recorded on video and shows Ma counting $50,000 (£38,000) in cash for the secrets they shared, federal prosecutors say.
While living in Hawaii in 2004 he took a job at the FBI’s Honolulu office as a contract linguist.
The FBI, already aware of his espionage activities “hired Ma as part of a ruse to monitor and investigate his activities and contacts”, prosecutors said on Wednesday.
According to the AP, the unnamed collaborator was Ma’s brother, who died before he could be prosecuted.
At a court in Hawaii on Wednesday Ma was jailed for 10 years, as agreed with prosecutors, followed by five years of supervised release.
“Let it be a message to anyone else thinking of doing the same,” FBI Honolulu Special Agent-in-Charge Steven Merrill said in a statement, according to the AP.
“No matter how long it takes, or how much time passes, you will be brought to justice.”
