California's attorney general has filed lawsuits against mortgage giants Fannie Mae and Freddie Mac, demanding that the companies that own some 60 percent of the state's mortgages respond to questions in a state investigation.

Attorney General Kamala Harris, whose office filed the lawsuits Tuesday in San Francisco Superior Court, is investigating Freddie Mac's and Fannie Mae's involvement in 12,000 foreclosed properties in California where they served as landlords. She also wants to find out what role the companies played in selling or marketing mortgage-backed securities.