NZ diplomat Robert Kaiwai had a hand in choosing $6.2m Hawaii mansion

Inside the the Hawaiian mansion MFAT bought for diplomat Robert Kaiwai. Photo / Supplied

A New Zealand diplomat was involved in the selection of a $6.2 million mansion bought with taxpayer money for him and his wife to live in.

However, the Ministry of Foreign Affairs and Trade (Mfat) has come out strongly against criticism that diplomat Robert Kaiwai picked the luxurious property, saying the decision was made by officials in Wellington.

"Mr Kaiwai was involved in identifying properties that corresponded with the terms of reference. A short list of five properties was made," an Mfat spokesman said.

"The short listed properties were then viewed by a three person Mfat team. Mr Kawai was neither part of that team nor present when they visited the properties."

The team made a recommendation to the Ministry, the spokesman said, which was reviewed by an independent advisory panel. The purchasing decision was made at a senior level in the Ministry.

The mansion was bought last year after Mr Kaiwai was named as New Zealand's first Consul-General in Honolulu, Hawaii.

It has four bedrooms, five bathrooms, a heated pool and its own waterfall.

The Consul-General position was created to engage with US officials on regional issues, and is also cross-accredited to Palau, the Federated States of Micronesia and the Marshall Islands.

When the cost of the mansion was reported on TV3's Story, the Taxpayers' Union was highly critical, and the lobby group has now hit out at Mr Kaiwai's involvement.

Its executive director Jordan Williams said Mfat had sent an official to Hawaii with "a blank cheque".

"It's little wonder he picked a St Stephen Ave style mansion with marble bathrooms and even its own waterfall."

Details of the Honolulu purchase come after controversy over the Government's purchase of an $11.4 million apartment close to the United Nations in New York for New Zealand's ambassador to the UN.

Labour criticised that purchase as evidence of a culture of extravagance.

Its foreign affairs spokesman David Shearer said it was unwise to involve Mr Kaiwai in the selection of the Honolulu property.

"I don't know what the property is like in Hawaii, and what you do need is something that would be fit to be able to represent New Zealand, and have people around for dinner because they do entertain. And I accept that.

"I don't question this person's honesty, but...there is a whole department inside MFAT equipped to do this sort of thing."

Foreign Minister Murray McCully said decisions on property were made by Mfat with advice from an independent property board to ensure value for money.

Specific questions about the Honolulu property should be referred to Mfat, Mr McCully said, but the Consul-General position had already been beneficial.

"Having a diplomatic presence in in Honolulu has allowed us to step up our engagement with the Northern Pacific, in areas of humanitarian aid, fisheries, and disaster risk management," Mr McCully said in a statement.

"Honolulu is also the seat of the United States military's Pacific Command (PACOM) which has responsibility in the region from India through to the US west coast. Our Consul-General is responsible for engaging with United States officials and experts regional security issues."