The supervisory committee shall make or cause to be made an annual audit and shall submit a report of that audit to the board of directors and a summary of the report to the members at the next annual meeting of the credit union; shall make or cause to be made such supplementary audits as it deems necessary or as may be ordered by the Board, and submit reports of the supplementary audits to the board of directors; may by a unanimous vote suspend any officer of the credit union or any member of the credit committee or of the board of directors, until the next members’ meeting, which shall be held not less than seven or more than fourteen days after any such suspension, at which meeting any such suspension shall be acted upon by the members; and may call by a majority vote a special meeting of the members to consider any violations of this chapter, the charter, or the bylaws, or any practice of the credit union deemed by the supervisory committee to be unsafe or unauthorized. Any member of the supervisory committee may be suspended by a majority vote of the board of directors. The members shall decide, at a meeting held not less than seven nor more than fourteen days after any such suspension, whether the suspended committee member shall be removed from or restored to the supervisory committee. The supervisory committee shall cause the passbooks and accounts of the members to be verified with the records of the treasurer from time to time, and not less frequently than once every two years. As used in this section, the term “passbook” shall include any book, statement of account, or other record approved by the Board for use by Federal credit unions.