In 1989, two Swedish tourists, Sven Urban Höglin and Heidi Paakkonen, went missing in the Coromandel. Mr Höglin's body was discovered by pig hunters in 1991, but Ms Paakkonen has not been seen since.

David Tamihere spent 21 years in prison for the 1989 murders of Sven Urban Höglin and Heidi Paakkonen.

The Swedish tourists and had gone tramping in bush near Thames in April. They were reported missing in May.

David Tamihere was convicted of their murders in 1990, he was granted parole late in 2010.

Convicted double murderer Roberto Conchie Harris claimed Tamihere told him he had sexually molested Ms Paakkonen and Mr Höglin, killed them and dumped their bodies at sea.

Mr Höglin's body was found in a shallow grave in 1991, but Ms Paakkonen has never been found.

In 2017, Harris was found guilty of lying to the court and in 2020 Tamihere's conviction was referred back to the Court of Appeal.

Investigative reporter Donna Chisholm has covered the story for years with all its twists and turns.

Go to this episode on rnz.co.nz for more details