Prime Minister John Key said he would not be concerned if the Auditor-General widens her inquiry into ministerial expenses.
Auditor-General Lyn Provost is looking into ministerial credit card use after Housing Minister Phil Heatley resigned from Cabinet over his misuse of his card.
Originally Ms Provost was asked only to look at Mr Heatley and the wider procedures at Ministerial Services, but Mr Key said it was up to her to decide what she looked into.
"She may well extend it, it's not my call," Mr Key said.
Mr Heatley's resignation followed the release of ministerial credit card statements to the media under the Official Information Act.
It was the first time the information had been released in that format and now Ministerial Services was dealing with requests for the previous administration's credit card statements as well.
Mr Key said the information would be released, but he had not asked any questions about Labour spending, nor had he been told about it.
He had no concerns about the implications of wider release and further investigation of them by the Auditor-General.
"My understanding is that it did not bring up any other areas of concern other than ones highlighted and I think there have been satisfactory answers as far as I am concerned... So I am not concerned about other National ministers. In terms of the previous administration I have not see that information, so I can't comment on it."
Mr Key said New Zealand's Parliament in comparison to others around the world was free of corruption and unethical behaviour.
He also asked the media to show some restraint in their coverage of MPs and ministers spending.
"The media do need to think a little bit about what is legitimate spending within the rules, even if they don't like the rules... If someone breaks the rules they are fair game, if some body complies with the rules, but the media doesn't like that, that doesn't make that person necessarily a bad person".
Mr Key believed that MPs and ministers were restraining their spending with the more transparent regimes of recent time.
Mr Key said there was intense media scrutiny of even the smallest expense claimed by MPs and ministers, and it wasn't unique to New Zealand.
Mr Key said he expected to have the Auditor-General's report in about three weeks.
More details of ministerial spending are expected to be released this week.