The Electoral Commission has ruled that no offence was committed by the New Zealand First Party secretary in relation to the party's 2007 annual return of donations.
But in a summary of a withheld decision, the commission said donations made to the party in 2005, 2006 and 2007 were not included in the party's returns.
New Zealand First has already updated its 2007 return and is now required to do the same for the two other years.
On 10 October, the Serious Fraud Office cleared the party of any fraud charges relating to donations channelled through the Spencer Trust.
At the time, it referred information to the Electoral Commission and to police.
In its statement on Thursday, the Electoral Commission issued a summary but said it was withholding the decision for now to avoid potential prejudice to a continuing police investigation.
New Zealand First leader Winston Peters said allegations about undeclared donations made to his party were always baseless.
The party has updated its 2007 return, to include an $80,000 donation from the Spencer Trust.
He said the party was given legal advice that it did not need to declare that donation in its original 2007 return.
Mr Peters said he was particularly pleased the party's secretary Anne Martin had been found not to have committed any offence.
Commission decision against ACT
The commission has also found that the ACT party should have disclosed it was provided with rent-free office space by businessman Sir Robert Jones for a number of years before 2005.
It too is required to amend its returns for the years it received rent-free office space.
The commission said the office space was valued at about $20,000 a year, and was a party donation under the Electoral Act 1993.
