Rubin "Hurricane" Carter says Bain, who is still facing five murder charges, will have a lot to deal with over the coming months.

Carter was wrongly imprisoned for 18 years for triple murder and now fronts Innocence International which works to exonerate prisoners. He says Bain has tough times ahead and has to "get himself together".

Carter's story inspired a Hollywood movie.

The former middleweight contender spent two hours with David Bain in 2001 and supports the decision to free him on bail.

"It is necessary when someone's conviction has been squashed to remove that person from that place of danger immediately so we are overwhelmed by finding out that David is in fact on bail," Carter says.

He is planning a trip to New Zealand to meet with Bain again and to help him adjust to life outside prison gates.

Retired judge Sir Thomas Thorp believes as many as 20 New Zealand inmates could have been wrongly convicted but until now there has been no US-style innocence lobby.

Victoria University is looking into around a dozen cases in an innocence project.

"We hope to help people who have been possibly wrongfully convicted with a long term view to improve the legal system in New Zealand," says Matthew Gerrie.