An investigation is underway after a massive house fire in Wellington CBD on Tuesday night.
The 'massive' house fire which broke out at a heritage building on Abel Smith Street is now under control.
Fire and Emergency is looking into unconfirmed reports people were inside the house at the time of the blaze.
Assistant area commander Matthew Abel said it was "a significant fire which required a lot of resources".
Over 10 appliances with 50 people were helping at the scene.
Abel said they are now looking into unconfirmed reports that there were people inside the house.
"We are working on that."
Fire crews plan to enter the Abel Smith Street house on Wednesday.
Abel said they have "no idea" how the fire started and police are helping with enquiries.
Firefighters were called to the blaze at 6:08pm on Tuesday night as smoke rose over the Wellington CBD.
A Newshub camerawoman said she could smell it from Parliament.
Terrace Tunnel and Arras Tunnel on State Highway 1 are closed due to the fire, Waka Kotahi NZ Transport Agency Wellington and the Police said.
"Please avoid the area and follow direction by emergency services on-site for an alternate route."
The house at 128 Abel Smith Street has had an interesting history since it was constructed in 1898.
It was first used as a home, then a private hospital, a society headquarters and is now a community centre and the Radical Social Centre and Community Whare.
The house was also raided by armed police in October 2007 as part of the Urewera Raids.
