The Court of Appeal has quashed Rex Haig's conviction for murder, more than 12 years after Southland fisherman Mark Roderiques went missing.
Haig served 10 years for Mr Roderiques' murder on his tuna fishing boat in 1994 before being paroled.
In June, he made a "last-ditch" effort to prove his innocence. Then, Justice William Young told the Crown the court had a "problem" with Haig's conviction.
Today the Court of Appeal released its decision, quashing the conviction and ruling there was to be no retrial.
During the June hearing, Justice Grant Hammond said a major factor against a re-trial would be that if Haig was convicted again, he would have to be given a fresh life sentence even though he had already served his time in jail.
The Court of Appeal's decision may have an impact on more than one murder decision - during the appeal it was asserted that Haig's nephew and crewman David Hogan was responsible for Mr Roderique's death.
Hogan was given immunity from prosecution and a $13,000 reward in exchange for testifying against Haig, but the successful appeal from Haig will raise the question of what to do about Hogan.
Hogan has also been implicated in the murder of Anton Sherlock, who had given a statement saying Hogan had admitted Mr Roderique's murder to him.
Another man, Nigel Johnstone, is serving a life sentence for Mr Sherlock's murder.
Mr Haig's lawyer, Jonathan Eaton, said in June an appeal was lodged for Johnstone at the same time as Haig's but no formal response had ever been given.