The Southern District Health Board is investigating after a patient allegedly set fire to a bathroom wall in a locked mental health ward at Dunedin's Wakari Hospital.
The blaze, which a firefighter said caused significant damage to the wall, broke out in Ward 9B just after 10am yesterday.
It is understood the patient started the fire with a fire lighter.
The Fire Service and police were called to the hospital at 10.16am.
Roslyn station officer Kate Hill said firefighters brought the blaze under control fairly quickly, but there was significant damage to a bathroom wall and, because there were no windows, it took a while to clear the building of smoke.
She said hospital staff allowed them access and were looking after patients away from the fire.
A fire safety investigation is being carried out.
Senior Sergeant Craig Brown, of the Dunedin police, said officers went to the hospital to assist staff, but there was no trouble with the patient.
A 23-year-old man was likely to face charges as a result of the incident.
A health board spokesman said staff evacuated other patients briefly when the fire broke out.
He had no comment about how the patient came to have a fire lighter, or whether he was allowed to have one, but confirmed the ward was non-smoking.
The board's investigation would look at all those issues, he said.
