The county election board shall not disturb anything in the transfer case, and the case shall remain sealed and retained by the secretary of the county election board until opened by court order or until it is necessary to open same for use at another election, at which time the ballots shall be destroyed; provided, however, that in no case shall the ballots be destroyed until thirty (30) days after the election at which they were cast. Provided, the secretary of the county election board shall be authorized to open a sealed transfer case for the purpose of conducting a post-election audit as described in Section 1 of this act.¹