Photo: RNZ / Angus Dreaver
The Electoral Commission has admitted 15 voting places had data entry errors, and more than 700 votes were left off the final vote announced on Friday.
However, the commission says the now-completed final checks of party, electorate and special votes have not resulted in any major changes to the overall results or allocation of seats.
News broke on Tuesday of three voting places that had data entry errors for the party vote result.
In a statement on Thursday, the Commission detailed further problems including 15 places that experienced data entry errors for electorate votes, one where special vote data was incorrectly entered, and five that counted election day votes as advance votes.
The East Coast electorate was the worst affected.
There, some 620 votes were not initially included in Friday's official count - despite having been included in the preliminary vote count on election night.
The corrections made have resulted in an extra 693 party votes being included, and 708 candidate votes, though this was not enough to change overall turnout which remained at 78.2 percent.
The commission said none of the errors affected judicial recounts.
The commission's chief electoral officer Karl Le Quesne said people should have confidence in the integrity of the official count and the amended results.
"We have corrected the errors found. These are small in scale and do not affect the overall results or allocation of seats. We apologise for these errors. It is disappointing they were not picked up in the quality assurance processes and falls short of our expectations."