Any member, officer or employee of the bank who is interested either directly or indirectly, or who is an officer or employee of, or has an ownership interest in any firm or agency interested, directly or indirectly, in any contract with the bank, shall disclose this interest to the board. This interest shall be set forth in the minutes of the board, and the member, officer or employee having the interest shall not participate on behalf of the bank in the authorization of any such contract.