Except as provided by state law, no member of the commission nor any officer or employee of the city shall have a financial interest, direct or indirect, in any contract with the city, or be financially interested directly or indirectly, in the sale to the city of any land, materials, supplies, or services, except on behalf of the city as an officer or employee. Any violation of this section shall constitute malfeasance in office and any officer or employee of the city found guilty thereof shall thereby forfeit his/her office or position. Any violation of this section, with the knowledge expressed or implied of the person or corporation contracting with the city shall render the contract voidable by the commission.