Dr Turner said signed documents between Team New Zealand and ACEA confirmed the Auckland event earlier this year and it was announced at a meeting with teams last month.
"We are not at the end of the road," he said. "They can't do this, they can't sign us up to a qualifier and then change their minds suddenly. It is subject to arbitration, we have some documentation that's been signed between us and the ACEA."
Dr Turner said it was no secret the Government would not provide additional funding if there was no Auckland event - but that stage had not yet been reached.
However, since the ACEA's announcement yesterday, Mr Key said it was now "extremely unlikely" the Government would give more funding to Team NZ.
"I expect there to be further discussions between [Minister for Economic Development] Steven Joyce and [Team NZ boss] Grant Dalton, but I think it's extremely unlikely there would be more funding."
He said he was aware of the arbitration, but it would be hard to justify funding if the lead-in regattas were in Bermuda.
"It makes it really difficult to make the case for more money."
He did not believe the $5 million the Government had already put in was wasted as the Government and Team NZ had been optimistic Auckland would host a regatta.
Team NZ sponsors Toyota and Nespresso also said it was too early to tell if the announcement would jeopardise their private funding agreements.
Auckland Mayor Len Brown said the council was still hopeful pending the arbitration process.
