KEY POINTS:
A campaign group founded by Rubin "Hurricane" Carter - the champion boxer wrongfully imprisoned for triple murder - believes Scott Watson is innocent.
Immortalised in a Bob Dylan song Hurricane and a 1999 film starring Denzel Washington, Carter was freed after spending nearly 20 years in jail and
later founded the Association in Defence of the Wrongfully Convicted.
Carter visited convicted killer David Bain in prison in 2001 before Bain was granted a retrial last year. Although Carter has since retired from the lobby group, director Win Wahrer said he was convinced Watson was innocent after reviewing the legal file sent to them by author Mike Kalaugher.
Wahrer says Watson's convictions for the murders of Ben Smart and Olivia Hope after the pair were last seen on New Year's Day 1998 were concerning "on many levels".
No bodies or murder weapon were recovered, evidence identifying Watson was "dismal", police had tunnel vision and key witnesses had recanted their evidence, Wahrer said.
"It appears there was a rush to solve this case and paint Mr Watson with an unfavourable brush. Much of the evidence does not stand up once thoroughly scrutinised," she said.
The association had written to New Zealand MPs in support of Watson and offered assistance to his family, lawyers and supporters.
The latest edition of its journal examines the Sounds murders' case, much of its report based on Keith Hunter's book Trial by Trickery and coverage in the Herald on Sunday and North & South magazine.
Key points highlighted by the Association in Defence of the Wrongfully Convicted were the revelations from ex-detective Mike Chappell - who was the systems manager for the police computer system and answered hundreds of calls about a mystery ketch. The boat does not match Watson's sloop.
Chappell told the Herald on Sunday last year that, after only a few days of answering calls, the inquiry team was told to ignore sightings of the ketch and focus on Watson.
His statements will form part of a petition to the Governor-General by Watson's defence counsel, Greg King and Mike Antunovic.
The Governor-General, in consultation with the Ministry of Justice, could refer the case to the Court of Appeal or even recommend Watson be pardoned. King said new evidence would be key to overturning Watson's convictions.
It includes key police witnesses Guy Wallace and Roz McNeilly retracting their evidence of picking Watson from a photo montage and a secret witness retracting his evidence that Watson confessed to him while in jail
"But doesn't it say it all when the father of Olivia Hope, who sat through the entire trial and bawled his eyes out, goes public with serious reservations about the convictions?" said King.
Nearly 10 years after Ben Smart and Olivia Hope went missing, Gerald Hope told North & South magazine that he was not sure if police had got the right man.
"What we got was a conviction but we never got the truth. And that's the part that still really rips me up. I'm not saying [Scott Watson] is not guilty. What I'm saying is let's clear up the doubt."