INVESTIGATORS from the Australian Transport Safety Bureau are seeking answers as to why a container freight train derailed at the town of Junee, 430km south-west of Sydney.
The incident occurred about 10pm on 7 June while the train was at Junee railway station.
According to the Bureau, the train crew were doing a roll by inspection at the time.
The train had derailed the trailing bogie of the fourth wagon and the leading bogie of the fifth wagon.
The down platform of the station was also reportedly struck, receiving minor damage.
As a result of the derailment the down main line was closed for repairs, impacting train services on the main south railway line.
The ATSB is to obtain information from the train data logger, track circuitry data and information about the track and rolling stock maintenance and conduct interviews.
The investigation is being led by the New South Wales Office of Transport Safety Investigations which conducts rail investigations in NSW on behalf of the ATSB.
A report is to be released at the end of the investigation.