Fire investigators are today examining the scene of a Welcome Bay house to find the cause of a blaze that gutted the unoccupied building.

Firefighters received multiple calls to the single level building, which was fully ablaze when they arrived at the scene in Waikite Road shortly after 10.30pm.

'The fire was contained and a fire investigator will be returning in the morning in daylight to try and ascertain the cause,” says Fire and Emergency NZ northern communications centre shift manager Paul Radden today.

"A neighbour told me that the house has been empty for a while and heard explosions coming from the property, a car was parked in the driveway, but unsure if anyone was in the house," a reporter at the scene told SunLive last night.