A 100-year-old homestead in Myocum was totally destroyed by fire on Saturday.
Neighbours of the house on a property at the corner of Benloro Lane and Tyagarah Road alerted police and fire authorities, but when they got there the house was already engulfed in flames.
Late yesterday a young man living in the house remained unaccounted for, but police do not fear for his safety.
Tweed-Byron police Inspector Greg Jago said no-one was injured in the blaze.
Five fire trucks from surrounding Rural Fire Service (RFS) brigades as well as a Fire and Rescue NSW truck from Mullumbimby arrived on the scene at around 12.30pm.
A spokesman said it took around three hours to extinguish the blaze but the timber home was completely gutted.
A police forensic team examined the site yesterday but the cause of the fire is still unknown.
Neighbours said an area where gas cylinders were kept appeared to be where the fire started.
The incident has prompted a reminder by fire authorities for residents to check the operation of smoke alarms in their homes by pressing the test button monthly and replacing batteries every six months.
While smoke alarms won’t save a house burning down, they do save lives by alerting those inside.