(a) Except as permitted by this section no contact or purchase involving an amount in excess of five hundred dollars shall be made by the city in which any officer or any member of his family has any financial interest, direct or indirect. A "contract" shall for the purpose of this section include any arrangement or agreement pursuant to which any materiel, service or other thing of value is to be furnished to the city for a valuable consideration to be paid by the city or is to be sold or transferred by the city, except the furnishing of personal services as an officer or employee of the city. The term "member of his family" shall include only spouse, child, grandchild, father, mother, sister, brother and the spouse of any of them.
(b) Without limiting the generality of paragraph (a) of this section, an officer shall be deemed to have a financial interest in a contract if he or any member of his family is an employee, partner, officer, director or sales representative of the person, firm or corporation with which such contract is made or a sales representative of such person, firm or corporation. Ownership, individually or in a fiduciary capacity, by an officer or member of his family of securities, of any corporation with which a contract is made or is a sales representative of any person, firm or corporation with which such contract is made, shall not be deemed to create a financial interest in said contract unless the aggregate amount of such securities or interest in such securities, so owned by such officer and the members of his family, shall amount to ten percent of any class of the securities of such corporation then outstanding.
(c) A contract in which an officer or member of his family has a financial interest may be made by the city if the members of the council having no such interest shall unanimously determine that the best interest of the city will be served by the making of such contract is made after comparative prices are obtained.
(d) Any officer who knowingly permits the city to enter into any contract or purchase in which he has a financial interest without disclosing such interest to the council prior to the action of the council in authorizing such contract, shall be guilty of misconduct in office. Except in the instances specified in paragraph (c) of this section, the unanimous determination (by vote or written instrument) of all members of the council that in a particular case an officer or member of his family will not have a financial interest in any contract or purchase to be entered into by the city shall be final and conclusive in the absence of fraud or misrepresentation.
(e) No officer shall stand as surety on any bond to the city or give any bail for any other person which may be required by the Charter or any ordnance of the city. Any officer of the city who violates the provisions of this paragraph shall be guilty of misconduct in office.