New Zealand anaesthetists will soon be studying ketamine as a solution to post-surgery pain.

Previous studies show at least one in eight patients who have major surgery develop long-term pain afterwards.

The researchers will be looking into whether ketamine - a class C drug - can ease this pain.

The subject's been granted nearly $5 million of research money by Australia’s National Health and Medical Research Council.

New Zealand researchers will be involved in the international study of nearly 5,000 patients who will be followed for 12 months after their surgery.