Someone reported at about 8:15 a.m. that a car was partially submerged in the Santa Fe Channel near the 800 block of Wharf Street, Banks said.
About three hours later, with the help of police, fire crews and a Contra Costa County sheriff's dive team, the car was removed from the water and a body was found inside, the chief said.
He said at about 12:15 p.m. that the body had not been identified, and that the person's gender had not yet been determined.
Banks said, however, that the car was registered to a man who lived aboard a boat in the Richmond Inner Harbor area.
The Contra Costa County coroner's office was being called to the scene.
Banks said investigators have not determined how long the car had been in the water or how it got there.
Crews from the California Department of Fish and Wildlife were also at the scene working to contain fluids that spilled from the car, fire officials said.