A US citizen working as a tour guide has been charged with spying for Chinese intelligence services, the US Department of Justice said.
Xuehua Peng delivered classified information to China’s Ministry of State Security (MSS), prosecutors said.
Mr Peng, 56, allegedly completed five “dead drops” at hotel rooms between 2015 and 2018.
He was arrested on Friday in Hayward, California, and denied bail at a court hearing.
“The conduct charged in this case alleges a combination of age-old spy-craft and modern technology,” US Attorney David Anderson said.
The FBI snared Mr Peng, also known as “Edward Peng”, as part of an elaborate “double agent operation” launched in March 2015.
A “confidential human source” – an FBI double agent – passed national security secrets to Mr Peng in return for payment, prosecutors said.
On six separate occasions, Mr Peng allegedly showed up at hotel rooms in California and Georgia to collect or drop off packages.
In four of those cases, Mr Peng allegedly retrieved an SD card containing classified information, before travelling to Beijing to meet Chinese intelligence officers.