New Zealand First leader Winston Peters spent time with his lawyers today while Prime Minister Helen Clark faced the music in Parliament.

National has accused NZ First of breaking the law after revelations the Spencer Trust paid at least $50,000 to NZ First in 2005 which was not declared.

NZ First is saying half of that was a donation from Sir Robert Jones which was not disclosed because of an administrative error, but offered no explanation about the other $25,000.

Donations over $10,000 have to be declared but because the breach is outside a six-month statute of limitations it cannot be prosecuted.

Two investigations are under way into donations to NZ First. Parliament's privileges committee is looking at whether rules were broken over a $100,000 donation from billionaire Owen Glenn while the Serious Fraud Office is investigating what donations from the wealthy Vela family and Sir Robert were spent on.

Accountant and auditor for the party Nick Kosoof issued a statement this evening saying the party made an administrative error by not declaring the Sir Robert donation.

The error happened during a change of administrative staff.

"This amount ($25,000) was correctly banked into (the) New Zealand First account on 7 September 2005, with other donations and unfortunately overlooked by error when recording in the office records as a donation over $10,000."

Mr Kosoof said the 2005 declaration would be amended.

NZPA contacted party president George Groombridge to ask about the issue and the other $25,000, but he would not comment.

Mr Peters' spokesman said he did not have answers and it was a party issue.

The partial clarification follows months of questions and follows the SFO obtaining the trust's full records, which Spencer Trust trustee Grant Currie confirmed to NZPA this afternoon.

"What was given was a complete record of the finances of the trust," he said.

"That's really a copy of my firm's trust account ledger for the trust because the trust didn't have another bank account of its own. So it was a complete record of all the financial records of the trust."

In Parliament, National leader John Key grilled Prime Minister Helen Clark on why she did not act earlier to clear up the Glenn donation controversy considering she knew about it in February.

Miss Clark revealed the conversation with Mr Glenn, in which he told her Mr Peters asked him for a donation and he gave it, on Thursday last week.

Mr Key said by failing to disclose what she knew, while Mr Peters held a press conference publicly denying the donation, Miss Clark had become "complicit in Mr Peters' attempts to mislead the New Zealand public" and he asked why she did not feel obliged to state what she knew.

"Did the Prime Minister not think that -- because this issue involved her minister of foreign affairs soliciting a large donation from a person soliciting to become the honorary counsel to Monaco -- she should have taken more action than simply observing there was a conflict of evidence and that in fact she should have forced a resolution of this conflict back in February?"

He accused her of turning a blind eye, withholding key evidence and standing back while Mr Peters turned the affair into a circus.

Miss Clark repeatedly said she did act -- she put it to Mr Peters who denied he or his party got the money.

"My assumption was that both men were honourable gentlemen and there may well be some innocent explanation."

Miss Clark said she sought assurances from Mr Peters in February and three times in July and he gave the same answer. He was emphatic that he had not solicited the money.

Under questioning, Miss Clark also said she had no involvement facilitating the donation, and was not told by Mr Glenn of any other donations to parties.

Miss Clark would not resile from her accusation yesterday that the National Party was leaked information about the SFO inquiry before Mr Key made his announcement National would not work with Mr Peters following this year's general election.

"Somebody somewhere in the government system had to be responsible for this leaping out into the public arena."

Mr Key said it was a "very serious matter" for Miss Clark to accuse the SFO of improper activity while it was investigating a party which supports her government.

Mr Peters is stood down from his ministerial roles while the SFO investigation is conducted.