The Labour Party is calling for more transparency about savings being reported on behalf of the country's district health boards.
The call came during a briefing at Parliament's health select committee on Wednesday.
Officials from the Office of the Auditor-General updated MPs about its latest audit work, including for Health Benefits Ltd.
It said HBL is working with DHBs towards making $700 million gross in savings over five years, for reinvestingt in health.
Labour's health spokesperson Annette King said she'd been unable to find out where the savings are coming from and pressed officials for detail.
They replied the savings are from individual DHBs and conceded that there is scope for more transparency by HBL in its reports.
They also said $114.6 million in total savings have beeen made by HBL for the sector since mid-2010.