However, Chambers said the issue appeared to revolve around the use of auctions in the 2016 and 2019 campaigns and what items should have been declared in the campaign returns.
"It's no secret that there was an auction during the 2019 campaign and there were a couple during the 2016 election campaign," he said.
Chambers wasn't campaign director in the 2016 election, but took up the role in time for the 2019 mayoral race. He said he was confident there were no grounds for further legal action.
"In the returns we filed we fully declared auction bids that were above the threshold of $1500 for donations."
Under the Local Electoral Act, donations under that amount don't have to be declared.
However, "there is a grey area where a competitive bid could become a donation and should be declared".
Chambers said he did not know who the complainant was, but he was keen to see the issue resolved.
"Reputations are at stake and until there's an outcome we can't close the chapter and move on."
Goff declined to comment. A spokesperson said he hadn't been contacted by the SFO to date, and directed the query to the agency.
Last September, electoral officer Dale Ofsoske passed a complaint about Goff's 2016 election expenses to police.
It centred around a $366,000 auction declaration which did not specify individual donations or purchases. It included the sale at an auction of a book for $150,000.
The book had belonged to Goff, a former minister of foreign affairs, and had been signed by Chinese President Xi Jinping.
Police made "a number of inquiries" but the timeframe for a possible prosecution expired in December.
At the time, Ofsoske said the complaint was under section 112D of the Local Electoral Act 2001 – "filing a false return of electoral donations and expenses".
It's not the first time questions have been raised about politicians and political parties using auctions as a means to secure political donations.
In 2017, the Labour Party was found to have hidden tens of thousands of dollars in donations behind over-inflated art auctions, naming the artists as donors instead of the secret individuals paying for the works.
The artists involved had no idea the party was naming them as the donors and they never saw a cent of the money. They said their works were auctioned off at well above market value to wealthy benefactors who wanted to keep their support for the party secret.
The Labour Party said the practice complied with electoral law. But one party member described the practice as "whitewashing" – a way to keep big donations private at a time when corporate contributions to political parties were falling because of public scrutiny.
University of Otago Law Professor Andrew Geddis said candidates and parties often used auctions to raise money for their campaigns. He said it could involve someone paying a large amount for an item that was above and beyond what they would normally pay for it.
He said it was important the public knew who paid the money at such auctions and who had been funding a party's or candidate's campaign.
Geddis said when local body candidates filed their expense and donation returns there was often no auditing or independent checking carried out.
Under the Local Electoral Act, returning officers had a limited window to take legal action over any irregularities found, he said.
However, the SFO has the ability to prosecute under the Crimes Act and isn't limited by such time frames.
