Auditor-General Kevin Brady could yet be called in to investigate a donation made by businessman Owen Glenn to New Zealand First leader Winston Peters' legal bills, says Prime Minister Helen Clark.
The $100,000 donation was made in 2006, but Mr Peters did not include it in his return of pecuniary interests.
Mr Peters says his lawyer told him about the donation only on Friday.
Miss Clark says she must take take Mr Peters at his word unless she has evidence to the contrary.
She says the question now is whether the donation is a pecuniary interest, and whether Mr Peters should have made a disclosure.
Miss Clark says the Registrar of Pecuniary Interests can refer matters to the Auditor-General, or independently take up the matter.
Mr Peters says there is nothing unusual or untoward in the contribution to a legal fund in 2006 by Mr Glenn, who is based in Monaco.
Mr Glenn donated $100,000 towards legal costs of an electoral petition in 2006.
Mr Peters says he was told of the donation only on Friday.
He says the money was to fund legal action and did not go to him personally or to his party.
Mr Peters said politicians should not know the source of large donations because it was vital there be some distance between politicians and those who donated large sums of money.
At a party conference on Saturday, Mr Peters said the donation was not illegal and was not made to New Zealand First - an explanation that New Zealand First supporters seem to have accepted.
Mr Glenn was the Labour Party's largest donor at the 2005 election.
National Party deputy leader Bill English says he believes the Labour Party had a hand in the donation, though he says his party has no evidence to back up the assertion.
Mr Peters' lawyer, Brian Henry, denies Labour Party president Mike Williams was involved.
