Each member of the Council shall have the power to administer oaths and affirmations in any investigation or proceeding pending before the Council. The Council shall have the power and authority to compel the production of evidence before it. Subpoenas may be issued in the name of the City and be attested by the City Clerk. Disobedience of such subpoena or the refusal to testify (upon other than constitutional grounds), shall be deemed contempt and shall be punishable as provided by the general laws of this State.