Charges have been filed against four people over donations paid into a National Party electorate bank account.
Leader Simon Bridges has not been charged, and neither has the party.
In a statement the Serious Fraud Office said: "The Serious Fraud Office filed criminal charges today against four people in relation to donations paid into a National Party electorate bank account."
"The defendants are scheduled to appear in the Auckland District Court on 25 February."
"The SFO will not make any further comment until any name suppression issues have been dealt with."
In October 2018, MP Jami-Lee Ross took a complaint against National leader Simon Bridges to police over a $100,000 donation.
Mr Bridges repeatedly denied all allegations.
In March last year, the electoral donation complaint lodged was referred to the Serious Fraud Office.
Mr Bridges denied asking Mr Ross to break up the donation into smaller sums so it would remain anonymous.
Donations under $15,000 are below the disclosure threshold.
“I have always maintained I had nothing to do with the donations. As I have always said the allegations against both myself and the Party were baseless and false,” National Party Leader Simon Bridges said in a statement.
“This was always just a vendetta by a disgruntled former MP.”