The Mayor, the City Administrator, the Controller, or any board or commission appointed by the Mayor, relative solely to the affairs under its control, may require such periodic or special reports of departmental costs, operations and expenditures, examine the books, papers, records and accounts of, and inquire into matters affecting the conduct of any department or office of the City and County, and for that purpose may hold hearings, subpoena witnesses, administer oaths and compel the production of books, papers, testimony and other evidence. The Board of Supervisors shall have the same powers of inquiry and review, including the power to issue subpoenas and compel the production of evidence, with respect to matters affecting the conduct of any department or office of the City and County.