Joseph Auga Matamata, 66, a chief, was convicted in March 2020 for bringing 13 Samoans to New Zealand and exploiting them for more than two decades. He was sentenced to 11 years in jail.
In April, he appealed his convictions arguing the trial judge had misled the jury over what constituted slavery, while the Crown appealed his sentence, saying it was too lenient.
But the Court of Appeal dismissed his bid in August. They also dismissed the Crown's bid to increase the man's 11-year sentence, but ruled he must serve at least five years in prison.