Australia II skipper John Bertrand has rejected claims that Ben Lexcen did not invent the famous winged keel that guided the yacht to America's Cup victory in 1983.
Lexcen's contribution came into doubt on Wednesday when Dutch naval architect Peter van Oossanen broke his silence after 26 years, saying he and his Dutch team, and Dutch aerodynamics expert Joop Slooff, were the main designers of the winged keel.
Dr van Oossanen said Lexcen played only a minor role -- perhaps 10% - in the revolutionary design.
But Mr Bertrand told AAP that Lexcen, who died in 1988, was the leader of the design team and the man who pulled the whole package together.
"There is no doubt that Ben was the principal designer for Australia II, and as to the winged keel, he worked with others, including van Oossanen, throughout the whole design process," Mr Bertrand said.
"He had the responsibility to pull the whole package together...and he did it in a brilliant manner." Mr Bertrand said Lexcen had been designing 18-foot skiffs in Sydney and putting end plates on keels and rudders 20 years before Australia II's winged keels.
He said there was one of Lexcen's skiffs bearing the end plates -- Taipan -- on show at the National Maritime Museum to prove it was his idea.
"Unfortunately, Ben is not here to defend himself and he is the only one who really understands the intricacies and who set the design process in motion," Mr Bertrand said.
He said the accusation that Australia cheated had been around for many years.
Australia II might have been disqualified from the America's Cup under rules that dictated that competing yachts had to be designed by citizens or residents of the competing country.
Mr Bertrand said the rules had since changed and anyone could design yachts for any country now.
Dr van Oossanen said he was given a $A25,000 gift from Australia II owner Alan Bond, which he now regarded as hush money for keeping the secret of the keel's origin.
"(Ben) was a very nice guy, I had a lot of time for him, he was a very likeable person, but after 25 years, I must say that he had very little to do with the design," Dr van Oossanen told ABC Radio on Wednesday.
"The predicament of course was that we weren't able to come out and say so, even though I had been brought up as an Australian, there was no way we could have said we participated in this process." Dr van Oossanen said he would have been happy taking the information to the grave, but he wanted the Dutch contribution acknowledged.
"Let the facts come out, let the truth come out and let's just face whatever is going to happen," he said.
Lexcen was made a member of the Order of Australia and had a car, the Toyota Lexcen, named after him.
