A multi-million dollar dispute involving the Southern District Health Board is being investigated by the Serious Fraud Office.

The health board has been in dispute with South Link Health over contract payments since 2002.

Neither party will disclose how much money is in dispute, but it could be up to $15m, counting interest.

The health board paid South Link Health more than $6m for savings achieved on service contracts.

At question is what that money was then spent on, and South Link Health maintains it has done nothing wrong - using it for approved programmes.

The health board is hoping for a settlement, regardless of the outcome from the Serious Fraud Office investigation.