A former CIA agent has pleaded guilty to spying for China, the US Justice Department announced on Friday.

Alexander Yuk Ching Ma was born in 1952 in Hong Kong, moved to Hawaii at a young age and became a naturalized American. He admitted that in 2001 he handed over a significant amount of classified US national security information in a meeting with Shanghai intelligence agents, even though he had not worked for the CIA for the previous 12 years.

The meeting was allegedly arranged by another former CIA agent, a naturalized American of Shanghai origin. On the third day of contacts at a Hong Kong hotel, Chinese agents offered “$50,000 in cash, which Alexander Yuk Ching Ma counted,” according to the US Justice Department briefing. The two men then “agreed to continue to assist” Shanghai’s intelligence agency.

In 2003 Ma was hired by the FBI in Hawaii to provide linguist services. The FBI knew of Ma’s ties to Chinese intelligence and recruited him to work in an isolated office “where his activities could be monitored,” the US Department of Justice said. Ma worked for the FBI until 2012.

The US Justice Department did not say how Alexander Yuk Ching Ma, who faces up to 10 years in prison, was exposed.