Listen to Newstalk ZB at 7pm Wednesday to hear the final instalment in NZME's investigation into the murders of Ben Smart and Olivia Hope.
It's hoped a new development against murderer Scott Watson will put the case to rest for good.
Investigative journalist Ian Wishart says an admission from key witness Guy Wallace, during an interview on Newstalk ZB yesterday, has further solidified Watson's guilt in the murder of Ben Smart and Olivia Hope 20 years ago.
Guy Wallace, a water taxi driver, says he dropped Ben Smart and Olivia Hope off at a boat with a mystery man.
He also reported seeing the mystery man at the Furneaux Lodge garden bar.
Journalist Ian Wishart told Tim Dower Mr Wallace seems to have finally twigged the mystery man was Watson.
"He didn't actually know Scott Watson but his subconscious memory has linked that face that he now knows and said, 'yep, saw him at the bar drinking a beer out in the garden beer tent'."
LISTEN ABOVE AS IAN WISHART SPEAKS WITH TIM DOWER