Monday marks the 20th anniversary of the disappearance of Ben Smart and Olivia Hope, two young people who were celebrating New Year's Eve in the Marlborough Sounds. Their bodies have never been found and Scott Watson was later jailed for their murders -crimes he and his supporters maintain he never committed. 

Twenty years on Herald Reporters Carolyne Meng-Yee and Mike Scott have teamed up to produce Chasing Ghosts - Murder in the Sounds, a podcast series and extended feature talking to many of those involved in the case who are still haunted by the tragedy.

Today we look back at the case against Scott Watson, speak to his father - who has helped lead the fight for his freedom - and hear from some of those who were also at Furneaux Lodge near where Ben and Olivia were last seen.

See the full digital feature here.

Listen to the podcast series on iHeartRadio here.

Newstalk ZB will broadcast Chasing Ghosts: Murder in the Sounds in three parts over three consecutive days between 6 and 7pm this Monday, Tuesday and Wednesday.