A "non-suspicious" electrical fault is to blame for a blaze which damaged Auckland's historic St James Theatre.
Emergency services arrived at scene around 10pm last night to find a fire in the basement.
Thirteen fire trucks were at the theatre at the height of the blaze.
The complex was closed after a fire in 2007 and re-opened earlier this year.
Senior station officer Barry Fox says there were some hazards for the crews.
"Ventilating the building, getting rid of the smoke out of the building," he told reporters at the scene.
Asbestos testing was carried out this morning and fire crews who had been at the scene overnight went through a decontamination process.
This delayed fire investigations, but the building was given all the all-clear of the harmful substance.
Principal trustee for the Auckland Notable Properties Trust who owns the property, Steve Bielby, said he expected the site to be fully cleared by officials by about 2.30pm.
"It's a significant fire but it's very isolated in the building.
"It hasn't actually caused that much damage to the building as a whole – there is more water damage from the fire sprinklers rather the fire itself," he said.
Mr Bielby said there were two or three events planned for the venue in the next month.
"But it could potentially be quite a quick fix," he said.
The fire doesn't appear to have spread from the basement.
"The minor fire in the St James is a reminder to us all to support the effort to ensure the restoration of this very fragile grand old lady," Auckland Mayor Len Brown posted to Facebook this morning.
Australian electronic duo What So Not, comprised of producers Flume and Emoh Instead, were due to take the stage on Saturday evening.
In a statement this afternoon, organisers Red Rum Touring said they are working to arrange a replacement venue.
"We'll have more details shortly, but for now the show must go on!"
Co-director Mike Ross said having the event would not go ahead at the theatre.
In April the theatre opened its doors to the public for the first time in eight years.
The iconic 87-year-old theatre was restored after being damaged by fire following an electrical fault.