A fire that has caused the evacuation of buildings and the closure of Manners St to traffic is thought to have been sparked by computer equipment.
Fire Service spokesman Murray Dunbar said the fire was started by computer equipment on the third floor of Sovereign House.
Eight fire engines and 32 firefighters had put out the blaze and were in the process of cleaning up after sprinklers were set off.
Mitch Czudaj, who works on the 11th floor, said the building was evacuated. Coming down the fire escape "black, dirty water" was seen coming down the walls on about the fourth floor.
Co-workers had smelled smoke, he said.
Dunbar said Manners St would be open to traffic again once the site had been cleaned up.
He said it was likely there would be water damage to the floors below.
There have been no injuries reported.
- The Dominion Post