Ten train carriages left the tracks between Narromine and Tomingley on Sunday, October 1.
The cause of the incident is currently unknown.
Australian Regional Tracks Cooperation (ARTC) have confirmed 10 wagons left their track between Narwonah and Wyanga just south of Narromine.
Police were alerted but no incident report was made as the train company is dealing with the problem.
“The independent rail safety investigator (Office of Transport Safety Investigator) has attended the site [on Monday morning] to commence their investigations into the incident,” an ARTC spokesperson has said.
“Around 100 metres of track has sustained damaged. Track repairs will start after the transport safety investigator releases the site and the derailed wagons are successfully recovered and removed from the location by the rail operator.
“We are working closely with our customers regarding alternative arrangements for planned train services impacted by this incident.
Witnesses have reported the train left the tracks on the Peak Hill Railway Road between Fairview Siding Road and Wyanga Road on a local family property.
Witnesses have been told it could take over a week to clean up the derailment.
“The forecast for a return to services will be reassessed as repairs are underway, but is currently expected to be during the weekend,” the spokesperson confirmed.
“ARTC will provide further updates through the week.”
Keep up to date with the train incident by checking the Narromine News Website or the Narromine News Facebook page.
A previous version of this story stated two carriages were derailed, ARTC has confirmed there were 10.