Marlborough Sounds murders: Scott Watson's boat painted for Ben Smart and Olivia Hope documentary

Chris Watson, father of convicted murder Scott Watson, onboard Scott's boat Blade in Picton Harbour. Photo / Tim Cuff

The boat where convicted double murderer Scott Watson was found to have killed Ben Smart and Olivia Hope has been painted for a television documentary - with taxpayers footing the bill.

NZ On Air has granted Production Shed more than $1 million to make the documentary, titled Ben and Olivia: Searching for the Truth, Fairfax reported.

The sloop where Watson killed Mr Smart and Miss Hope, whose bodies have never been found, is moored at Waikawa Marina.

Boat builder Richard Clausen confirmed to Fairfax that he was approached last month by the production company asking to paint the boat, named Blade.

Scott Watson continues to maintain his innocence. Photo / John Kirk-Anderson

It is currently a red-orange colour, the same as it was on the night Watson is believed to have murdered the pair after a New Year's Eve party at Furneaux Lodge in the Marlborough Sounds.

Mr Clausen told Fairfax that the production company wanted to repaint the Blade blue, to match the colour Watson painted the boat after the murders. Police say he painted the vessel in a bid to disguise it.

Watson's father Chris Watson, who owns the boat, allowed Production Shed to use the vessel because having it as part of a documentary was "good publicity".

He told Fairfax he was always willing to help "showcase the ridiculous way this case has been represented".

"The police and the courts did a hatchet job so there's nothing anyone can do that's worse than that."

Watson continues to maintain his innocence.

NZ On Air told Fairfax that neither Watson nor his family would be benefit financially from the documentary.

"The Blade has been repainted to its colour at the time of the disappearances for the dramatic recreations and will be returned to its pre-shooting state," the agency stated.

Mr Hope's father Gerald Hope said he had "no issue" with the NZ On Air funding.

"My greatest concern is that they represent the events and the facts surrounding Ben and Olivia's disappearance accurately and honestly."