xxx xxx xxx 5. Three (3) envelopes, each containing a key to a padlock of the ballot box which shall be delivered, under proper receipt, by the election officer to the provincial election supervisor, the provincial prosecutor and the provincial treasurer. In the case of cities whose voters do not vote for provincial officials, and municipalities in the National Capital Region, the election officer shall retain one envelope and distribute the two other envelopes to the city/municipal prosecutor and city/municipal treasurer, as the case may be. xxx xxx xxx The ballot box, all supplies of the BEI and all pertinent papers and documents shall immediately be delivered by the BEI, accompanied by watchers, to the city/municipal treasurer. For this purpose, the city/municipal treasurer shall, if necessary, keep his office open all night on the day of the election and shall provide the necessary facilities for said delivery at the expense of the city/municipality. Section 52. Omission or erroneous inclusion of documents in ballot box. - If after locking the ballot box, the BEI discovers that some documents or articles required to be placed in the ballot box were not placed therein, the BEI, instead of opening the ballot box in order to place therein said documents or articles, shall deliver the same to the election officer. In no instance shall the ballot box be reopened to place therein or to take out therefrom any document or article except in proper cases and with prior written authority of the Commission, or its duly authorized official, to retrieve copies of the election returns which will be needed in any canvass. In such instance, the members of the BEI and the watchers shall be notified of the time and place of the opening of said ballot box. However, if there are other copies of the election returns outside of the ballot box which can be used in the canvass, such copies of the election returns shall be used in said canvass and the opening of the ballot box to retrieve copies of the election returns placed therein shall then be dispensed with. In case the BEI fails to place the envelope containing the counted ballots inside the ballot box, the election officer shall, with notice to parties, deposit said envelopes in a separate ballot box which shall be properly sealed, padlocked and stored in a safe place in his office. Said ballot boxes shall remain sealed unless otherwise ordered by the Commission. As made abundantly clear by the foregoing provisions, the mode of preserving the ballots in this jurisdiction is for these to be stored safely in sealed and padlocked ballot boxes which, once closed, shall remain unopened unless otherwise ordered by the Comelec in cases allowed by law. The integrity of the ballots and therefore their probative value, as evidence of the voters’ will, are contingent on the integrity of the ballot boxes in which they were stored. Thus, it is incumbent on the protestant to prove, at the very least, that the safety features meant to preserve the integrity of the ballot boxes and their contents were installed and that these remained in place up to the time of their delivery to the Comelec for the revision proceedings. If such substantial compliance with these safety measures is shown as would preclude a reasonable opportunity of tampering with the ballot boxes’ contents, the burden shifts to the protestee to prove that actual tampering took place. If the protestee fails to discharge this burden, the court or the Comelec, as the case may be, may proceed on the assumption that the ballots have retained their integrity and still constitute the best evidence of the election results. However, where a ballot box is found in such a condition as would raise a reasonable suspicion that unauthorized persons could have gained unlawful access to its contents, no evidentiary value can be given to the ballots in it and the official count reflected in the election return must be upheld as the better and more reliable account of how and for whom the electorate voted.