Key Points:

National Party leader John Key has bought a holiday home in Maui, the second largest island in Hawaii.

The deal for the apartment was settled a week ago, Mr Key told the Sunday Star-Times. He did not disclose what he paid for the apartment or its location.

"You can see the beach," he said.

Key said he had not declared the property in the Register of Pecuniary Interests of Members of Parliament because it was owned by his family trust, the JP and BI Key Family Trust.

While MPs have to declare family trusts, they do not have to declare what the trusts own.

Mr Key confirmed the Key family trust owned six properties.

Apart from the Hawaiian property, there was an apartment in London used by his niece and four properties in New Zealand -- a property in Wellington, the family home in Auckland and an Omaha beach property, north of Auckland.

Mr Key said he owned a similar number of properties to Prime Minister Helen Clark.

She declared five properties - her home in Auckland, a town house in Wellington, an apartment in Christchurch, an investment property in Rodney and a house in the United Kingdom inherited from her father-in-law.