A major house fire that could have affected three units was averted when a cleaning supervisor just happened to be checking a property prior to guests arriving on Friday.

L J Hooker's cleaning supervisor went to inspect Unit 1, Bellview in Cobbadah Street and raised the alarm.

Fire, police and ambulance services raced to the site on Friday afternoon to find thick black smoke coming from the middle level of the three storey units.

Jindabyne Fire Captain, David Farmer said that an electrical fault in the sauna was believed to be the cause of the fire and the burning cedar wood inside the confined space had created "horrific" smoke levels.

Six fire officers were sent into the building in breathing apparatus to deal with the fire.

Captain Farmer reported that the fire had completely destroyed the sauna and caused smoke and heat damage to the ceiling above. There was also smoke damage to both of the other attached units, the second one being most heavily smoked logged.

In the course of dealing with the fire, officers also had to attempt a possum rescue in the unit although the possum wasn't being very co-operative.

Despite being frightened, the possum was finally revealed to be living in the garage area and fled to a nearby tree.