Police have slammed claims in Ian Wishart's book which say the evidence line followed into the murder of Ben Smart and Olivia Hope was wrong.
In a statement released today, Police Detective Superintendent Peter Read outlined three claims in Mr Wishart's book Elementary which they disagree with after comparing it with the original investigation file.
However, police do agree with Mr Wishart's book that Scott Watson murdered Ben and Olivia.
Mr Read rejected his claim that Scott Watson and the unknown accomplice removed Ben and Olivia's bodies on 1 January, 1998, in Shakespeare Bay.
Police also disagreed that Mr Watson painted his boat while sailing near the head of Endeavour Inlet on the New Year's Day while he had another unknown person on-board and that evidence of the Erie Bay sighting was false.
"While we understand the enduring public interest in this case, police are not in a position to publicly re-litigate evidence which has been gathered during a historic investigation, including evidence which was put before the court."
Mr Read said each claim had been considered and the file examined before making the findings public. It was not unusual for witness sightings to contradict each other, he said. But police and prosecutors made decisions on who gave evidence based on corroborated accounts that were supported by the known facts.
Mr Wishart is standing by his story and said today's announcement was nothing more than a "factually incorrect butt covering exercise" that had overlooked the vital evidence.
The investigative journalist said Mr Read was unaware of key witness statements when he briefed him about their differing findings.
"While police acknowledge that I am right about Watson being the mystery man and Alliance being the mystery ketch, they are trying to discredit evidence that shows they got the Erie Bay story wrong."
He said the witness statements were proof that police were wrong as three witnesses said the boat was blue before it arrived in Erie Bay and another man Ted Walsh saw it being repainted from red to blue on New Year's Day.
"Mr Read appeared to be unaware of the statement and confused Walsh with a different witness."
He instead claimed police were relying on evidence from Watson's key advocate, Paul Maker, that he helped him paint the boat on January 2 even though they had never interviewed him at the time of the murders and his earlier statement was contradicted by other witnesses.
Mr Wishart also believed there were statements from three witnesses who claimed they had seen two people onboard Watson's boat Blade.
"The police have cherry-picked the files to try and discredit a book that shows their trial reasoning was wrong. They missed a chance to really investigate Watson's movements in the crucial 36 hours after the murders, and they are trying to make excuses."
Olivia Hope's father says he is pleased the book prompted police to review evidence in the case.
Talking to Newstalk ZB's Larry Williams today, Mr Hope said in his book Elementary, author Wishart went through evidence and witness statements to come up with a set of "other pieces of a jigsaw" which met his requirement to put a different scenario together.
"My mind is very clear and I try to keep things in perspective: thousands of witness statements," Mr Hope said.
"The police had to prepare a Crown case and they selected the evidence which they believed in good faith would be adequate and was proven to be so with the conviction of Scott Watson."
He said he did not have an issue with Wishart's book, and was pleased it had led to police reviewing the evidence and coming out with their own rebuttal.
Mr Hope called the book insightful and said some of its conclusions had been revelationary.
"It was a twist to the tale."
Though he did not want to perpetuate the case, he said he and his family were still looking for closure.
"I'm still hoping we can find the truth in this.
"Irrespective of Watson's conviction, the loss of two young people is uppermost in my mind."