The lawyer for eight police officers and a military officer convicted of rape says the real assailants remain free.
Earlier this month the court found the men guilty of the rape and sexual assault of Vilikesa Soko two years ago.
Thirty-year-old Mr Soko was arrested in connection to a robbery in Nadi in August 2014, and later died in Lautoka Hospital as a result of the injuries he sustained.
Another man, Senijeli Boila, was also assaulted.
Lawyer Iqbal Khan has filed an appeal on 40 counts, saying the judge who sentenced the men to up to nine years jail time, erred in dismissing the evidence of Mr Boila who said that none of the nine had assaulted him or Mr Soko.
Mr Khan said there is no question over what happened to Mr Soko but he said his clients were not the culprits.
"We don't dispute the facts. We said that they were assaulted by somebody but not the accused persons," he said.
"We are saying that the state has not proved beyond reasonable doubt that this was the persons who had done it. And in fact Boila, in his evidence he gave full names of other officers who assaulted him. What we are saying, is that the judge should have stopped the case against these guys and directed that somebody else should have be charged. That's our complaint."
Mr Khan said he expects the appeal to be heard in the new year.
The Fiji police are yet to comment about the claim that they arrested the wrong men who were initially also charged with manslaughter over Mr Soko's death.