Me. Rev. Stat. tit. 21-A, § 763

As soon as the ballots have been counted, the applications, where required, absentee ballots, return envelopes, lists required by sections 753‑B and 756 and other election materials must be repacked, in accordance with section 698, and returned to the clerk. The clerk shall keep them in the clerk's office for the time required by section 23.