When the yacht Australia II stormed through the America's Cup fleet to win the coveted cup in 1983 it created the biggest wave in the iconic race's history.

For the first time in 132 years, a non-American yacht had dominated the race, and as stunned Americans faced up to the disappearance of their trophy from its place in the New York Yacht Club, Australians danced in the streets.

Now that historic win is being challenged by a Dutch naval architect who claims that he designed the legendary winged keel that propelled the boat to victory, and not Ben Lexcen, the Australian boat designer who has been famously credited with the design.

Peter van Oossanen, whose Dutch design team worked with Mr Lexcen and the Dutch aerodynamics expert Joop Sloof on the design of Australia II, has told Australian media that Mr Lexcen played only a minor role in the boat's design and was not even present during the "eureka moment" in the keel's development.

Under the America's Cup rules — which at the time stipulated that competing yachts should be designed by residents or citizens of the countries that they represented — this would mean that Australia II should have been disqualified from the race, and the trophy handed to the defender, the American yacht Liberty skippered by the Dennis Connor.

Dr Van Oossanen told the Sydney Morning Herald that he was breaking 26 years of silence over the authorship of the design because he has grown tired of what he believes is an air-brushing from history of the Dutch role in the boat's victory.

"Ben was a nice guy," he told the paper. "He had a flair for things, a flair for shapes. But he wasn't a scientist and he wasn't able to understand the full physics of what was going on."

Mr Lexcen, who died in 1988, contributed only five or 10 per cent to the design, he said.

"He left [the Netherlands where the designs were being drawn up and tested] to go back to Australia before the vital tank tests," he said. "The role he played was a minor one. Ben did things by feel and intuition, but in the America's Cup that will get you nowhere. It is a very scientific thing."

Doubts over Mr Lexcen's input date back to 1983 when the Americans began a legal action against the design of Australia II, which failed to disualify the Australian challenge. But this is the first time that it has been declared outright that the Australians were not the rightful winners of the trophy.

Dr Van Oossanen, who in 1983 was the chief scientist at the Netherlands Ship Model Basin in Wageningen, where much of the development work on Australia II was done, said he believed that the boat deserved its victory, particularly when weighed against the Cup's murky history of foul play and espionage. But now he says, under the strict rules of the race, the Australians were guilty of cheating.

The vital elements of the boat, which ensured her win, was a small hull over an upside-down keel with its famed, and controversial winglets. These were not only not designed by Mr Lexcen, said Dr Van Oossanen, but were not even his ideas.