Fire damages Dunedin cathedral after $150,000 restoration

An investigation is underway into a fire at Dunedin's St Paul's Cathedral, which just underwent extensive restoration.

Eight fire crews were called to the cathedral at 3:30am on Tuesday, which is one of Dunedin's most recognisable buildings in the heart of the Octagon.

"On arrival, we found a fire burning up near the roof structure," senior Dunedin station officer Simon Smith told Newshub.

"We've used multiple fire-fighting hoses, and an aerial appliance... to extinguish the fire."

But it comes only just after the cathedral underwent a $150,000 restoration including new skylights and a refurbished organ.

Dean of Dunedin reverend Dr Tony Curtis said they only unveiled the changes on the weekend.

"[We] had three great services, a lovely concert. So it was a bit sad to get the news this morning that we're going to have a bit more of a job."

But he was grateful for the quick response by emergency services and their care.

The relief fire crews managed to avoid water damage to the 101-year old Willis organ, although some of its 3500 pipes may need servicing. A brand new grand piano was also spared.

The water damage remained heaviest on the cathedral's lower level.

"As soon we can, we'll be open again. Services will be happening, and we'll go back to our mission with God's help," Rev Dr Tony Curtis said.

Initial inspections suggest the fire started by accident although the exact cause is still being investigated.