They say there's nothing to hide and if that's the case then New Zealand First has to show us the blank sheet.
If politics is about perception, the blurred lines between the NZ First Party Foundation and the party itself, doesn't look good.
Winston Peters should have learned by now that to leave an issue to bubble away eventually leads to a boiling cauldron where control is lost.
Think of the Owen Glenn donation saga in the lead-up to the 2008 election where he was stood down while an investigation took place, which saw Peters cleared, as he insisted he would be, but the damage was done.
The party never made it back into Parliament that election.
The latest allegations are that the NZ First Foundation's financing of the party could be in breach of the Electoral Act.
The party says it isn't.
Donations to the foundation don't have to be declared in the way that they do for money given to political parties.
New Zealand First insists the two are separate entities.
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The National Party also has a foundation, which questions have been raised about in the past.
Under that capital-protected foundation, contributions to it are, at least according to the party, never removed from it but are instead invested to ensure a stable and diverse revenue stream to support the party's activities.
It shouldn't be forgotten that the party's leader, Simon Bridges, is at the moment being investigated by the Serious Fraud Office for a donation received from a Chinese businessman which was apparently split into bite-size sums to allegedly disguise the real, single donor.
That's the trouble with our system where parties have to fund themselves and have to declare sums above a piffling amount.
It's probably a fair argument that the taxpayer shouldn't be brought in to fund parties for expensive election campaigns and the like, even though we do cough up cash for their advertising campaigns.
In Australia, the taxpayer pays for elections but money also comes from the corporate sector, which is theoretically declared through their Electoral Commission. It's theoretic because some donors hide their identities through associated entities.
Surely it's time in this country where a party should be able to scrape the cash together with an unlimited ceiling on the amounts donated. They should be declared to avoid the possibility of cash for policies.
If a company or an organisation likes the cut of a party's ideological cloth then surely it's fair that they're free to use their resources to ensure that party's in government.
The trade union movement's been doing it for the Labour Party since the year dot. Not only that, they're involved in selecting the leader and other party functions and no one seems to complain.
Why? Because it's transparent and there's a general expectation that a Labour-led government would lean towards providing the bread and butter of the union movement - assisting the needy.