The Southern District Health Board has refused to release a report it commissioned that identified $30 million in health savings.
The board cited commercial sensitivity and its right to conduct negotiations in its decision yesterday.
The PricewaterhouseCoopers report was part of work for which the cash-strapped board paid $358,000 to the business services company.
The report, which identified the savings over a three-year period, was presented to the board's closed-door audit and risk committee earlier this month.
The board has previously said the money would be saved through better use of the primary care sector, fast-tracking patients through hospital and better aligning staff rosters to workload.
The Otago Daily Times has complained to the Office of the Ombudsman about the board's refusal to release the report.