VANCOUVER -- An investigation into the massive 2017 wildfire that engulfed nearly 192,000 hectares in B.C.'s south-central Interior has found it was likely caused by smoking or smoking materials.

Called the Elephant Hill fire, the blaze started near Ashcroft on July 6 and, at its peak, forced thousands to evacuate, including the entire community of Cache Creek. 

BC Wildfire Service had completed its review in the fall of 2017, but as the BC Prosecution Service was considering charges following an RCMP investigation, those details were not released. 

But Mounties and the wildfire service said their investigations didn't uncover enough evidence to identify a person whose actions started the fire, so charges couldn't be laid. 

During the investigation, several other potential causes were eliminated including lightning, an escaped campfire, open fire activity, arson, railroads, vehicles or utility lines. 

The BC Wildfire Services said smoking materials can include matches, cigars, pipe tobacco cigarettes or marijuana. 

The wildfire service said its investigation is now complete and it won't be taking any further action. 

With files from The Canadian Press