Prime Minister John Key is being accused of breaching Parliamentary privilege by the Labour Party, which says he has knowledge of assets owned by a trust meant to be blind.
Labour MP Pete Hodgson is asking the Speaker to refer the matter to the Privileges Committee.
Mr Key set up a blind trust when he became Prime Minister to hold a number of investments and assets which is meant to ensure there is no potential for conflict of interest issues.
But Companies Office records show a company called Whitechapel set up soon after the 2008 election now owns assets previously held by Mr Key and his wife, including interests in an Otago vineyard, a dairy investment fund and an Auckland property firm.
One of Whitechapel's two directors is Mr Key's family trust lawyer, Kenneth Grey Whitney.
Mr Key says Labour is desperate, making things up and the party has no credibility or proof.
The Prime Minister says he has not heard of Whitechapel before the matter was raised with him in the past couple of days and is unaware of any details about shares and assets managed by his trust.
However, Mr Hodgson says he does not believe that for a minute and claims Mr Key has misled Parliament.