Team New Zealand has dismissed claims the design of the new America's Cup boats has been copied.
A Brazilian naval architect says the canting foil system on the AC75 infringes on the patent of his own design.
Manoel Chaves says he has given the Cup defenders until Friday to respond formally.
The team says he has no grounds for the accusation and claim they responded in July.
"Every good idea has 1000 fathers," said Team New Zealand in a statement.
“The design of the AC75 foil cant system has not been copied or inspired by Mr Chaves' design in any way, nor does it infringe any patent."
“As we have explained to Mr Chaves, his patent requires features not found in the AC75 yacht,” said the team.