The Council, the Mayor, or any person or committee authorized by either of them, shall have power to inquire into the conduct of any department, office, officer or employee of the City and to make investigation as to City affairs, and for that purpose may subpoena witnesses, administer oaths, and compel testimony, the production of books, papers, and other evidence. It shall be the duty of the Mayor to designate a police officer to serve such subpoenas. The Council shall provide by ordinance the penalty or penalties for contempt in refusing to obey any such subpoena, or to produce such books, papers and other evidence, and shall have the power to punish any such contempt in the manner provided by ordinance.