Crime scene officers are sifting through bushland at Mount Kembla following the discovery of skeletal remains.
The bones, believed human, were found on Wednesday, September 27, during the early stages of digging work on the Illawarra Escarpment Mountain Bike Network, a long-awaited labyrinth of trails that has been hailed a tourism game-changer for the region.
Police have declined to comment on Thursday's discovery, other than to confirm a police operation is underway.
"Officers from Wollongong Police District are conducting a search of bushland and we are unable to provide further information at this time," a spokesman said, in a statement.
Crime scene officers have brought shovels and sifting gear to the site as the police operation continues on Thursday.
The Mercury understands police have so far recovered a partial human skeleton.


Police are expected to consult missing persons records as part of the early stages of their investigation.
Contractors broke soil on the mountain bike trail project on Thursday, September 14, starting at a site just off a bush trail, off Harry Graham Drive.
The police operation is unfolding in that same area against the sound of revving bikes, with the site less than 400m from the boundary of Wollongong Motorcycle Club, which is teeming with school holiday riders.
According to National Parks and Wildlife Service, construction work on the bike tracks will continue.
"NPWS will continue work on a different part of the mountain bike track network while the police investigation is underway," a spokeswoman said.
