Since American billionaire Peter Thiel was granted New Zealand citizenship in 2011 without meeting residency requirements, only two others have been granted citizenship in the same way.
Both were newborn babies.
Mr Thiel was granted citizenship under exceptional circumstances despite not having lived in the country previously and not intending to do so in the future.
Internal Affairs figures show only two newborns, in 2014, have been granted citizenship in the same circumstances.
The Paypal co-founder had visited New Zealand four times when the government granted him citizenship. Internal Affairs has refused to say how many days he spent in the country.
The Ombudsman is investigating whether the refusal to make this information public is justified.
Normally a permanent resident has to spend more than 70 percent of their time in New Zealand over five years before they can apply for citizenship.
Mr Thiel, 49, who was also one of the first investors in Facebook, has bought and sold properties here, including a house in Auckland and a multi-million-dollar lakefront estate in Wanaka.
A few months after Mr Thiel was granted citizenship in June 2011, his firm Valar Ventures finalised a partnership with the government-funded New Zealand Venture Investment Fund.
Valar Ventures ended the partnership last October by activating a buy-out option.
It allowed Valar Ventures to make about $30 million from its input of between $7m and $9m, while the fund returned about $10m from the same input.