The Wellington High Court has heard arguments over the lawfulness of recommendations made by the Auditor-General about the wage subsidy scheme.
The judicial review hearing took place on Monday and Tuesday.
It was initially filed late in 2022 by the Gama Foundation, a Christchurch philanthropic organisation.
The group argues the Auditor-General could have done more to help the government retrieve billions of dollars wrongly obtained or retained by businesses under the Covid-19 Wage Subsidy Scheme.
The case focuses on a draft recommendation the Auditor-General made to the Ministry of Social Development to write to all recipients of the wage subsidy reminding them of their obligations.
The court must determine whether the Auditor-General's decision to change that recommendation to a targeted group of recipients was lawful.
Lawyers on both sides made submissions about the political independence of the position, and the Parliamentary privilege and reasonableness of that decision.
Kristy McDonald KC, a lawyer for the Auditor-General, argued the decision was held in documents covered by Parliamentary privilege - which protects the internal business of the House from scrutiny by the courts - and cannot be judicially reviewed.
The applicant's lawyer, Tiho Mijatov, disagreed, saying the decisions themselves are not subject to any special protections and need to be aired out in public.
He said public good would be served by having the court advise the Auditor-General to reconsider his decision.
Justice Andru Isac KC said he needed to properly consider the issue of Parliamentary privilege and ruled some specifics of the case could not be reported by the media.
Justice Isac reserved his decision until a later date.