Some city officials in San Francisco are extorting contractors for money by threatening their jobs, says a former San Francisco Supervisor. This comes during a federal investigation into the city’s high-ranking public officials, in which the city’s former director of Public Works, Mohammed Nuru, admitted in January to receiving bribes from multiple contractors in exchange for securing city contracts and expediting permit approvals. “The culture at City Hall has certain rules in place that allow a bad actor like Nuru … basically make them [contractors] give him money. Otherwise, he’s going to interfere in their ability to retain the contract or to complete the contract without ending up with problems,” Matt Gonzalez, public defender and former president of the San Francisco Board of Supervisors, said on EpochTV’s “California Insider” program. In a fair process of bidding, contractors are competing against one another and the lowest bidder who’s already qualified will …