The conviction was quashed by the court but Matangi Tonga reported the former prime minister's appeal against conviction on one count of possessing gun ammunition, without a licence, failed.
In July 2015, the then prime minister had written a letter of support for two Chinese people trying to obtain passports.
But the Appeal Court found there was no evidence that Tu'ivakano intended to deceive.
Tu'ivakano had been found guilty on 9 March at the Nuku'alofa Supreme Court and given a suspended two-year sentence.
