Several tonnes of coal waste at a former coal preparation plant was one of a few underground coal fires to ignite in the blaze.

The plant, part of Catherine Hill Bay's colliery infrastructure, was closed about a decade ago.

The fill on top of the old tunnel caught alight during the fire and has continued to waft smoke across the suburb.

Residents alerted LakeCoal, which is responsible for the site, when the smoke started to smell.

The company is expected to start excavating the area this week.