Convicted murderer Scott Watson. Photo / Supplied
It was the early hours of New Year's Day in 1997 when it happened.
Ben Smart and Olivia Hope were among 1500 revellers at a party at Furneaux Lodge in the Marlborough Sounds in the South Island of New Zealand.
The pair, who had been friends since they were young, decided to turn in and made their way to the boat where Olivia was staying over the New Year period.
But when they arrived the boat was chocka - the beds were all taken and there was nowhere left for them to sleep.
They grabbed sleeping bags and jumped on board a water taxi, planning to go back to shore and find somewhere to crash for the night.
A man on the taxi offered them a spot on his boat and the pair, eager to get to sleep after a long night of celebrating, accepted.
The taxi pulled up at the man's boat and dropped the trio off.
After that, Ben and Olivia were ever seen again.
Scott Watson was convicted of both murders but has always maintained his innocence and continues to push his case before the courts.
In today's episode of Herald podcast A Moment In Crime, senior journalist Anna Leask revisits the case.
Listen to the latest episode here:
A Moment In Crime is written, hosted and produced by Anna Leask with help from the NZME sound and vision team.
Leask has been covering crime and justice for the Herald for more than a decade and has reported on most of the major incidents and events over that time.
"Each month I'll take you inside some of our most infamous incidents, notorious offenders and behind the scenes of high-profile trials and events to show you what's really happening in your backyard," she said.
"Heroes and villains battle for justice to be done, and it seems no matter how horrifying the story, we always want to know more.
"If you want to know more about the cases that have shocked and shaped our nation - from murders and massacres to violent villains and the utterly unbelievable - join me for A Moment In Crime."
In our first episode, we looked back at the Christchurch terror attack - what unfolded on March 15 and how it changed New Zealand.
The podcast has also delved into the cold case murder of Kayo Matsuzawa, the murder of Feilding farmer Scott Guy, the cold case of schoolgirl Alicia O'Reilly, double killer Jason Somerville - infamous for the Christchurch House of Horrors, and the Lundy and Crewe family murders.
NZME has a raft of other podcasts produced by journalists and broadcasters from the Herald, Newstalk ZB, ZM, The Hits and others - all available on iHeart radio.
To subscribe to A Moment In Crime visit iHeartRadio, Apple Podcasts, Google Podcasts and Spotify.
If there is a case you'd like us to consider covering email anna.leask@nzme.co.nz
The 19-year-old disappeared without her wallet or mobile phone.