Senior Sergeant Anthony Bond, of Dunedin, said police were called to assist Fire and Emergency New Zealand with an investigation into a house fire in Mulford St in Concord at 5.55pm on Saturday.
The fire was caused by a lit cigarette that was left to "smoulder away" on a couch within the home.
Snr Sgt Bond reminded people who chose to smoke indoors to extinguish the cigarette or remains properly.
A Fenz spokesman said two appliances responded initially to a report of a house fire, one crew from Dunedin and one from Roslyn.
When crews arrived they found a fire within the basement of the home.
All people were out of the property and accounted for, the Fenz spokesman said.
A second alarm was raised and crews called for a specialist team to assist with decontamination of the site following the fire.
With any kind of smoking or cooking people needed to make sure everything was being attended to at all times, the Fenz spokesman said.
"People should not leave things unattended and if people are smoking inside they should take all precautions they are fully extinguishing the cigarette when finished."
A Hato Hone St John spokesman said one ambulance and one rapid response vehicle were dispatched to the scene.
One person was assessed and treated at the scene. They did not require transport to hospital, he said.
