Any Village officer or employee who has a substantial financial interest, direct, indirect or by reason of ownership of stock in any corporation, in any contract with the Village or in the sale of any land, material, supplies or services to the Village or to any contractor supplying the Village, shall make known that interest to the Mayor and Council and shall refrain from voting upon or otherwise participating in his or her capacity as a Village officer or employee in the making of such sale or in the making or performance of such contract. Any Village officer or employee who willfully conceals such a substantial financial interest or willfully violates the requirements of this section shall be guilty of malfeasance in office or position and shall forfeit his or her office or position. Violation of this section with the knowledge, express or implied, of the person or corporation contracting with or making a sale to the Village shall render the contract or sale voidable by the Mayor or Council. A "substantial financial interest" as used herein, shall be deemed to be an interest amounting to more than five percent of the particular business enterprise or contract.