Luxury car dealer, celebrated yachtie and kiwi Rich Lister Neville Crichton, 71, is due to wed fiancee Nadi Hasandedic, 38, next weekend in Sydney.
Delighted wedding guests in Auckland said this week they had received invitations "which are essentially a book" to the extremely lavish event to be held at the University of Sydney's historic Great Hall.
Guests said they would pack formal attire for what promises to be one of Sydney's society events, reported to cost around $A1 million ($1.08m).
However, a spokesman for Crichton strenuously denied that figure.
"There are 250 people attending the wedding, but the cost is an exaggeration. It is nowhere near that, but Neville does not wish to provide a specific figure.
"Neville and Nadi looked at a number of venues in Sydney, but when they saw the Great Hall they fell in love with this historic and beautiful building and the unique atmosphere it will provide for their wedding. The scale of the building and its design mean that it is able to be intimate when required, but also provide all the space and facilities required for their guests," the spokesman said.
"It's going to be incredible," predicted one guest and close friend.
Crichton, who has won the Sydney-to-Hobart yacht race, is nicknamed Croaky after he had his voice box removed many years ago. He talks through an artificial implant by pressing a small hole in his neck.
He appeared on last year's NBR Rich List with a $130m fortune and is said to be Australasia's largest independent vehicle importer via his company Ateco Automotive which oversees distribution of brands including Maserati and Ferrari in New Zealand and Australia.
In January, he sold his Sydney mansion in the top suburb of Point Piper for more than A$60m ($64m). That waterfront property, Portofino, was said to be the third-most-expensive property in Australia, according to a report from Australia's property business, Domain.
In 2015, the couple attended the New Zealand Business Hall of Fame event at The Langham. There, they were photographed, her with an arm around his shoulder.
Crichton has bought a new house for around A$33 million ($35m), on the same Point Piper waterfront. He was moving into that this week.
Sydney's Daily Telegraph reported: "Colourful eastern suburbs racing and business multi-millionaire Neville Crichton will marry his much younger fiancee Nadi Hasandedic on May 13 in the University of Sydney's historic Great Hall."
Hasandedic was born in Bosnia.
Invitations show the ceremony starts at 4pm, followed by canapes and drinks on the university's quadrangle lawns.
When he received a New Zealand national honour in 2012, his citation for the Insignia of a Companion of the New Zealand Order of Merit for services to yachting and business said he had transformed New Zealand's yacht and automotive industries and had also helped cancer sufferers.
"His vision, leadership and sporting passion have placed him at the forefront of yacht racing, representing New Zealand in regattas around the world with 174 race wins, and playing an instrumental role in establishing the New Zealand super-yacht industry as a world leader. He has mentored and inspired young sailors."
The citation said he had developed a career as a leading car importer and successful racing driver and, following his own recovery from throat cancer, he had helped develop methods to allow people to talk after a laryngectomy, providing support and inspiration for people suffering throat and associated cancers.