Any Municipal officer or employee who has a substantial financial interest, direct or indirect, or by reason of ownership of stock in any corporation, in any contract with the Municipality or in the sale of any land, material, supplies or services to the Municipality or to a contractor supplying the Municipality shall make known that interest and shall refrain from voting upon or otherwise participating in his capacity as a Municipal officer or employee in the making of such sale or in the making or performance of such contract. Any Municipal officer or employee who willfully conceals such a substantial financial interest or willfully violates the requirements of his section shall be guilty of malfeasance in office or position and shall forfeit his office or position.