When asked by media to explain his comments about Huka Lodge, Mr Peters said he received the information from "an inside source" in the real estate world.
"My informant says that John Key has given these people an assurance that, 'don't worry about it, we'll smooth it through the Overseas Investment Office'."
Overseas Investment Office (OIO) manager Annelies McClure said the OIO had not received an application to purchase the lodge.
"Huka Lodge is currently owned by Worldwide Leisure Limited, which, in turn, is owned by Dutch company Saraceno Holdings Limited BV, which received OIO consent to purchase the land in 2003," Ms McClure said.
"While this does not preclude the possibility that Worldwide Leisure Limited has entered into a sale agreement for Huka Lodge, the OIO has not received an application from any potential purchaser."
Mr Peters later said on Twitter: "The OIO application for Huka Lodge will take some time to be lodged and processed".
A statement released from the resort's general manager Kerry Molloy said: "Huka Lodge, has been under the same ownership now for 30 years, it has not been for sale, it is not for sale and has not been sold to anybody. The statement made by Mr Peters is not correct".
Huka Lodge director David McGregor also denied any knowledge of the sale.
"I'm a director, I'm in touch with what goes on, but I'm unaware of any negotiation or the fact that it may have been sold," he said.
Land Information Minister Maurice Williamson said Winston Peters' claim was "not true".
"The Overseas Investment Office has spoken to Huka Lodge director and shareholder David McGregor, and he has confirmed no sale has been made or is being considered," he said in a statement.
"Huka Lodge was last sold in 2003, following Overseas Investment Commission approval, when a Labour Government was in power."
Founded in the 1920s, Huka Lodge is perhaps New Zealand's most famous retreat. According to its website, famous guests have included Bill Gates, Rupert Murdoch, Dick Cheney, Sir Edmund Hillary and Queen Elizabeth II.
Huka Lodge is owned by Dutch-born businessman Alexander van Heeren who, according to his website, divides his time between Europe, the Pacific and southern Africa.
Mr Peters delivered his address on Auckland's North Shore today to a captivated crowd of Grey Power members.
The NZ First leader stuck to familiar touchstones, reminding his audience he had successfully brought in the Gold Card, warning of the dangers of immigration and reminiscing about New Zealand's golden years.
New Zealand has become a country with assets to be sold and wages to be lowered, Mr Peters said.
Mass immigration had resulted in masses of the Grey Power members' children and grandchildren flocking to Australia where they were treated as second-class citizens, he said.
"We are not doing as well as we once did ... we want again to be a proud nation."
The country had been run like a trading company for the past 30 years, with little leadership and even less vision, Mr Peters said.
"We have become a business with deals to be done, assets to be sold and the cost of labour to be reduced."
The current Government was hanging out work visas "like an eight-armed octopus" to foreigners, while thousands of New Zealanders couldn't get a job, Mr Peters said.
The next government needed to take a serious focus to immigration, he concluded.
Mr Peters also refused to speculate on any "sordid pre-election deals" NZ First might make. "Speaking bluntly ... we don't know how to play cards we haven't been dealt yet."
Speaking to media following his address he backed up his statement saying: "It puts you in a very weak negotiating position, the guy that knows what you want has got you covered, it's the oldest rule in the book".
