Police will investigate a suspicious blaze that destroyed at least 15 homes in a rural hamlet in northern NSW.

Authorities believe the fire that ripped through the Rappville on Tuesday may have been deliberately lit, in what Emergency Services Minister David Elliott says would be a truly “bastard act”.

Police and fire investigators have formed a strike force to determine the cause of the fire.

Assessment teams yesterday were still confirming how many properties had been lost or damaged in the blaze.