A fire which destroyed a $60 million super yacht at an Auckland boat builder's yard will result in job losses, the company has confirmed.

Fire investigators are still working to determine the cause of the fire, which broke out at McMullen and Wing yacht and boatbuilding in Mt Wellington at about 1am on August 12, but arson had been ruled out.

The vessel at the centre of the fire, Star Fish, was a 50-metre super yacht being built for Hong Kong-based Aquos Yachts, which had only half a year to go until completion.

A hundred people had been working on the project for the last two-and-a-half years, and commercial manager Michael Eaglen said the fire had been devastating for all involved.

Though the extent of the damage was still being assessed, he said there would inevitably be redundancies.

He would not discuss the number who would lose their job because it was "early days" in the company's discussions with staff.

"The guys are pretty resilient, they're putting on a brave face but it's absolutely heartbreaking," Eaglen said.

Much of the hull and lower parts of the yacht were made of steel and aluminium, and still intact.

However, he said it was a long process to find out how much of the materials were actually salvageable.

The same was the case for the overall cost of the blaze.

"We're adding that up and it's a big number," Eaglen said.

McMullen and Wing has a long history of building luxury and high-performance yachts and was the brawn behind New Zealand's America's Cup winning yacht Black Magic.

- © Fairfax NZ News