It has emerged that a complaint has been laid about a trust used to fund two of Auckland mayor Len Brown's election campaigns.
Police are investigating after a former police prosecutor, Grace Haden, complained that Mr Brown's electoral returns did not list contributors as required under the Local Electoral Act at the time.
Instead they used the name of the new Auckland Council Trust.
Grace Haden said her complaint was laid with the council a year ago, and police were still working on it despite investigating it since February.
She said Len Brown received more than $750,000 from the trust during his 2010 and 2013 election campaigns, and if he would not reveal the names of his contributors he should resign.
A spokesperson for Len Brown referred inquiries about the trust to the election campaign team, which has not returned calls.