Police received a call at about 8:40 p.m. from a neighbor who reported that the door to a house in the 2200 block of Lupine Road had been left open all day, Harrington said.
When officers went to the house to check on it, they discovered more than 500 marijuana plants being grown inside.
The growers, who were not there when police arrived, had rewired the electricity to bypass the house's meter in order to steal power from PG&E. They had also set up grow lights on timers inside the house and cut holes in the walls for ventilation, Harrington said.
Damage to the property is estimated to be about $70,000, Harrington said, and the city has red-tagged it because the rewiring has made it unsafe.
Police contacted the homeowner, who told them he had rented the property last August. The owner has been cooperating with the investigation.
Officers returned to the house Monday and spent about five hours removing the plants.
Investigators have also been talking to neighbors in an effort to identify potential suspects, but as of this afternoon, no arrests had been made, Harrington said.
Anyone with information about the case is asked to call Sgt. Tim Stratmeyer at (510) 799-8275.