(Left to right) Mayor Ed Lee and his wife Anita Lee talk with Senator Dianne Feinstein in his office before his Inauguration at City Hall on Friday, January 8, 2015 in San Francisco, Calif.

(Left to right) Senator Dianne Feinstein talks with House Minority Leader Nancy Pelosi who holds her granddaughter Bella Kaufman, 5, as they stand on stage after former Secretary of State Hillary Rodham Clinton (not shown) spoke at the DCCC Ultimate Women's Power Lunch at the Fairmont Hotel on Monday, October 20, 2014 in San Francisco, Calif. less

(Left to right) Senator Dianne Feinstein talks with House Minority Leader Nancy Pelosi who holds her granddaughter Bella Kaufman, 5, as they stand on stage after former Secretary of State Hillary Rodham Clinton ... more

U.S. Sen. Dianne Feinstein — turns out a few years ago her driver was passing on political information to his Chinese “handlers.”

A staffer in U.S. Sen. Dianne Feinstein’s San Francisco office was fired a few years back after being linked to Chinese spying in the Bay Area.

According to a Politico Magazine story on Silicon Valley espionage, the Feinstein staffer was suspected of providing political intelligence — but nothing classified — to his handlers, with one former intelligence official telling author Zach Dorfman that the suspected informant was “run” by officials based at the local Chinese Consulate.

A local source who knew about the incident confirmed to us that the FBI showed up at Feinstein’s office in Washington, D.C., about five years ago to alert the then-chairwoman of the Senate Intelligence Committee that her driver was being investigated for possible Chinese spying.

“Dianne was mortified,” said our source, who spoke to us only on condition he not be named.

Besides driving her around when she was in California, the staffer also served as gofer in her San Francisco office and as a liaison to the Asian American community, even attending Chinese Consulate functions for the senator.

According to our source, the intrigue started years earlier when the staffer took a trip to Asia to visit relatives and was befriended by someone who continued to stay in touch with him on subsequent visits.

That someone was connected with the People’s Republic of China’s Ministry of State Security.

“He didn’t even know what was happening — that he was being recruited,” says our source. “He just thought it was some friend.”

The FBI apparently concluded the driver hadn’t revealed anything of substance.

“They interviewed him, and Dianne forced him to retire, and that was the end of it,” says our source.

“None of her staff ever knew what was going on,” the source added. “They just kept it quiet.”

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call (415) 777-8815, or email matierandross@ sfchronicle.com. Twitter: @matierandross