SAN FRANCISCO (REUTERS) - A naturalised US citizen working as a tour guide in the San Francisco area was charged on Monday with being an agent of the Chinese government, providing officials there with classified US national security information.

Peng Xuehua, also known as Edward Peng, was taken into custody on Friday in Hayward, California, and was denied bail during an initial court appearance before a US magistrate judge that same day, federal prosecutors said at a Monday (Sept 30) morning news conference.

"The conduct charged in this case alleges a combination of age-old spycraft and modern technology," US Attorney David Anderson said.

"Defendant Xuehua (Edward) Peng is charged with executing dead drops, delivering payments, and personally carrying to Beijing, China, secure digital cards containing classified information related to the national security of the United States," Anderson said.

Peng, 56, is not accused of obtaining the classified information from the US government himself, but is charged with acting as a courier who between October 2015 and June 2018 left money at "dead drops" in hotel rooms in US cities and picked up secure digital cards.

He then allegedly travelled to Bejing with those cards to deliver them to his handlers in the Chinese government, according to the criminal complaint.

Peng, who works as a tour and sight-seeing operator for Chinese tourists in the Bay Area, faces a maximum sentence of 10 years in prison and a US$250,000 fine if convicted, prosecutors said.

He has been ordered to return to court in San Francisco on Oct 2.