Teina Pora's lawyers and supporters say his compensation offer from the government for crimes he never committed is several million dollars short of what he deserves.
The government has offered Mr Pora just over $2.5 million and unreservedly apologised to him for his wrongful conviction and nearly 22 years of imprisonment.
But his supporters said the Crown has ignored its own independent reviewer's recommendations on the compensation figure.
A criminal lawyer close to the case, Gary Gottleib said retired High Court Judge Rodney Hansen QC, in his report recommended the figure should be adjusted for inflation but the government ignored it.
"(The report said) consideration should be given to adjusting compensation payable to Mr Pora for loss of liberty to reflect the decline in the value of money.
"So he should have got on that recommendation well over three, closer to four million and the government decided not to take that very strong recommendation."
Watch the reaction from members of Teina Pora's legal team - Jonathan Krebs, left, and Ingrid Squire:
The compensation was based on 1998 guidelines which award $100,000 a year for loss of liberty.
Otago University law professor Mark Henaghan said it was unfair to use the guidelines without adjusting for inflation.
"In today's figures it's worth less than what it would have been in 1998 when these guidelines were drawn up.
"So in 1998 we felt it was fair that people should get $100,000 for every year they spend in prison when they are innocent of a crime. Well in 2016 that $100,000 is worth quite a lot more than that now."
Teina Pora's lawyers sited other cases, including that of Arthur Allan Thomas who was paid over $4m in today's money after spending nine years in prison for the Crewe murders that he did not commit.
His brother Desmond Thomas said based on those figures Mr Pora should get much more than $2.5m.
"That's no compensation. Cut all these big figures off the top of it first. He doesn't get two and a half million, he owes money to his lawyers and then there were other people that helped him as well.
"The Thomases believe that Teina Pora should get at least 10 million after what we've experienced."
The Police Association said it supported compensation and an apology from both the government and the police.
President Greg O'Connor said it was impossible to put a figure on 20 years and the government was working to a formula.
"A hundred million wouldn't be enough for some people. However, it's taxpayers' money, the government has to work to a formula, they appear to have done that, so fair or unfair it's their decision and I think we have to follow it."
Mr O'Connor said the government may need to review its formula for compensation and look at adjusting for inflation in the future.